generic: add MutexMap

.gitea/workflows/CI.yaml

@@ -1,6 +1,6 @@
 name: CI
 
-on: [push]
+on: [push, workflow_dispatch]
 
 jobs:
   # These steps build the `gas` docker image.

.golangci.yaml

@@ -60,8 +60,6 @@ linters:
         - -ST1000 # Re-enable this once we have docstrings
         - -ST1003 # I like snake_case
         - -ST1013 # HTTP status codes are shorter and more readable than names
-      dot-import-whitelist:
-        - "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
   exclusions:
     generated: lax # Don't lint generated files
     paths:

cmd/main.go

@@ -5,6 +5,8 @@ import (
 	"os"
 
 	"github.com/spf13/cobra"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/version"
 )
 
 const (
@@ -16,12 +18,16 @@ const (
 func main() {
 	root_cmd := &cobra.Command{
 		Use:           "gas",
+		Version:       version.String(),
 		SilenceErrors: true,
 		SilenceUsage:  true,
 	}
+	// Print a bare version string ("v0.0.4"), rather than cobra's "gas version v0.0.4".
+	root_cmd.SetVersionTemplate("{{.Version}}\n")
 	root_cmd.AddCommand(sqlite_lint)
 	root_cmd.AddCommand(cmd_init)
 	root_cmd.AddCommand(generate_model)
+	root_cmd.AddCommand(cmd_version)
 	if err := root_cmd.Execute(); err != nil {
 		fmt.Println(RED + err.Error() + RESET)
 		os.Exit(1)

cmd/subcmd_generate_models.go

@@ -6,11 +6,12 @@ import (
 	"go/ast"
 	"go/token"
 	"os"
+	"slices"
 
 	"github.com/spf13/cobra"
 
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/codegen/modelgenerate"
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
 )
 
@@ -23,22 +24,22 @@ var generate_model = &cobra.Command{
 	Args: cobra.ExactArgs(1),
 
 	RunE: func(cmd *cobra.Command, args []string) error {
-		path := Must(cmd.Flags().GetString("schema"))
-		modname := Must(cmd.Flags().GetString("modname"))
+		path := must.Get(cmd.Flags().GetString("schema"))
+		modname := must.Get(cmd.Flags().GetString("modname"))
 		sql, err := os.ReadFile(path)
 		if err != nil {
 			return fmt.Errorf("reading path %s: %w", path, err)
 		}
 		db := schema.InitDB(string(sql))
-		schema := schema.SchemaFromDB(db)
-		table, isOk := schema.Tables[args[0]]
+		sch := schema.SchemaFromDB(db)
+		table, isOk := sch.Tables[args[0]]
 		if !isOk {
 			return ErrNoSuchTable
 		}
 
-		if Must(cmd.Flags().GetBool("test")) {
-			file2 := modelgenerate.GenerateModelTestAST(table, schema, modname)
-			PanicIf(modelgenerate.FprintWithComments(os.Stdout, file2))
+		if must.Get(cmd.Flags().GetBool("test")) {
+			file2 := modelgenerate.GenerateModelTestAST(table, sch, modname)
+			must.Do(modelgenerate.FprintWithComments(os.Stdout, file2))
 		} else {
 			decls := []ast.Decl{
 				&ast.GenDecl{
@@ -51,10 +52,9 @@ var generate_model = &cobra.Command{
 							Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"`},
 						},
 						&ast.ImportSpec{
-							Name: ast.NewIdent("."),
 							Path: &ast.BasicLit{
 								Kind:  token.STRING,
-								Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"`,
+								Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"`,
 							},
 						},
 					},
@@ -69,6 +69,9 @@ var generate_model = &cobra.Command{
 				modelgenerate.GenerateSaveItemFunc(table),
 				modelgenerate.GenerateDeleteItemFunc(table),
 			)
+			if table.HasSoftDelete() {
+				decls = append(decls, modelgenerate.GenerateSoftDeleteItemFunc(table))
+			}
 			if table.IsWithoutRowid {
 				decls = append(decls,
 					modelgenerate.GenerateGetItemBy(table, table.PrimaryKeyColumns()),
@@ -78,13 +81,27 @@ var generate_model = &cobra.Command{
 					modelgenerate.GenerateGetItemByIDFunc(table),
 				)
 			}
-			for _, index := range schema.Indexes {
+			for _, index := range sch.Indexes {
 				if index.TableName != table.TableName {
 					// Skip indexes on other tables
 					continue
 				}
-				if index.IsUnique && len(index.Columns) == 1 {
-					decls = append(decls, modelgenerate.GenerateGetItemByUniqColFunc(table, table.GetColumnByName(index.Columns[0])))
+				if slices.Contains(index.Columns, "") {
+					// Skip expression indexes; there's no way to resolve an expression to a real column
+					continue
+				}
+				if index.Origin == "pk" && table.IsWithoutRowid {
+					// Already generated above, as the primary-key getter
+					continue
+				}
+				cols := make([]schema.Column, len(index.Columns))
+				for i, colName := range index.Columns {
+					cols[i] = table.GetColumnByName(colName)
+				}
+				if index.IsUnique {
+					decls = append(decls, modelgenerate.GenerateGetItemBy(table, cols))
+				} else {
+					decls = append(decls, modelgenerate.GenerateGetItemsBy(table, cols))
 				}
 			}
 			decls = append(decls, modelgenerate.GenerateGetAllItemsFunc(table))
@@ -94,7 +111,7 @@ var generate_model = &cobra.Command{
 				Decls: decls,
 			}
 
-			PanicIf(modelgenerate.FprintWithComments(os.Stdout, file))
+			must.Do(modelgenerate.FprintWithComments(os.Stdout, file))
 		}
 
 		return nil

cmd/subcmd_init.go

@@ -9,7 +9,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/codegen"
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 )
 
 var cmd_init = &cobra.Command{
@@ -23,11 +23,11 @@ var cmd_init = &cobra.Command{
 		var target string
 		if len(args) != 0 {
 			target = args[0]
-			PanicIf(os.MkdirAll(target, 0o755))
-			PanicIf(os.Chdir(target))
+			must.Do(os.MkdirAll(target, 0o755))
+			must.Do(os.Chdir(target))
 		} else {
 			// Default to current directory (".")
-			target = Must(os.Getwd())
+			target = must.Get(os.Getwd())
 		}
 
 		// Get all the config values
@@ -41,9 +41,9 @@ var cmd_init = &cobra.Command{
 			}
 		}
 		pkg_opts := codegen.PkgOpts{
-			ModuleName: Must(cmd.Flags().GetString("module")),
-			DBFilename: Must(cmd.Flags().GetString("db")),
-			BinaryName: Must(cmd.Flags().GetString("binary")),
+			ModuleName: must.Get(cmd.Flags().GetString("module")),
+			DBFilename: must.Get(cmd.Flags().GetString("db")),
+			BinaryName: must.Get(cmd.Flags().GetString("binary")),
 		}
 		if pkg_opts.ModuleName == "" {
 			pkg_opts.ModuleName = filepath.Base(target)

cmd/subcmd_version.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/version"
+)
+
+var cmd_version = &cobra.Command{
+	Use:   "version",
+	Short: "Print the version of `gas`",
+	Args:  cobra.NoArgs,
+
+	Run: func(cmd *cobra.Command, args []string) {
+		fmt.Println(version.String())
+	},
+}

doc/TODO.txt

@@ -1,13 +1,6 @@
 TODO: soft-deletion
-- enable soft-deletion if table has `is_deleted` and `deleted_at` fields
-- if soft delete is enabled, DeleteXyz should do update (not delete) and set is_deleted and deleted_at
-    - ...and DeleteXyz should have pointer receiver for soft-delete
 - GetXyzByID should include `ErrItemIsDeleted` if item is soft-deleted
 
-TODO: migration-structs
-- Right now, migrations are strings.  Could be a struct with "name", "up" and "down" fields
-- Adding a "down" operation enables handling newer DB versions with "down instead of error-out" for development (perhaps a flag)
-
 IDEA: migrations-table
 - Store migrations in a table.  This makes the schema more self-documenting.
 - Possible schema: name, sql_up, sql_down, hash (computed from those fields plus previous migration hash)
@@ -22,16 +15,26 @@ TODO: codegen SaveXyz update path doesn't check foreign keys
 - Insert path has FK error handling, but the update path wraps everything in Must
 - An update that violates an FK constraint will panic instead of returning an error
 
-TODO: codegen `without rowid` tables properly
-
 TODO: generated test file inclues global test DB setup, which is wrong
 
 TODO: join-tables
 - handle codegen for without rowid tables properly
 - add "get all X for Y"
-
-TODO: create a Getter function for each unique index
+- Example: `chat_pinned_messages`
 
 TODO: consider CreateDB and CreateMemoryDB
 
 TODO: generate tests for the remaining CRUD, try to hit ~100% default test coverage
+
+TODO: test reporter
+- coverage: https://x.com/wispem_wantex/status/2009799380648505563
+    - Jest shows for each file: % of lines, functions, branches and statements covered
+    - Go reporter should show:
+        - group coverage stats by either function, file or package
+        - count by statements, branches or functions
+        - Show both raw count and percentage
+        - list which lines / branches / functions were missed
+        - pretty (terminal) format or JSON format
+
+TODO: foreign key to compound-FK table
+    - sample: booru_post_tag_votes

doc/gas-stack.md

@@ -29,6 +29,12 @@
 
 - `ops` directory
 
+### Reinventing the wheel
+
+Wheels aren't difficult to invent; the concept is very simple.  However, there's many different types, shapes and sizes of wheels.  The wheel on a shopping cart is different from the wheel on a bicycle, a car, a tractor, a train, a spool of thread, etc.
+
+Reinventing the wheel is good.  It's good to use things that are specifically built for your purpose, with exactly the set of features and affordances you need.  Using a wheel that was made by someone else for a different purpose can be faster at first, but it's likely that their needs were different from yours.
+
 ### Borrowed from Ruby On Rails
 
 - Convention Over Configuration

doc/links.txt

@@ -1 +1,3 @@
 https://astexplorer.net/
+https://github.com/dave/dst
+https://disaev.me/p/writing-useful-go-analysis-linter/

ops/compile.sh

@@ -1,3 +1,10 @@
 #!/bin/sh
 
-go build -tags fts5 -o gas ./cmd
+# Stamp the version into the binary.  `git describe` fails when this isn't a git checkout (e.g. a
+# source export with no .git dir); in that case leave it empty, and pkg/version falls back to the
+# build info that the Go toolchain embeds.
+VERSION=$(git describe --tags --always --dirty 2>/dev/null)
+
+go build -tags fts5 \
+    -ldflags "-X git.offline-twitter.com/offline-labs/gas-stack/pkg/version.Version=$VERSION" \
+    -o gas ./cmd

ops/devcontainer/Dockerfile

@@ -1,13 +1,13 @@
 # A dev container.
 
-FROM alpine:3.22
+FROM alpine:3.24
 
 RUN apk add build-base git go sqlite vim shellcheck curl jq sudo bash docker
 
 # Busybox `less` doesn't appear to support colors (makes git diff lose color)
 RUN apk add less
 
-RUN curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b /usr/local/bin v2.0.2
+RUN curl -sSfL https://golangci-lint.run/install.sh | sh -s -- -b /usr/local/bin v2.14.0
 RUN GOBIN=/usr/local/bin go install git.offline-twitter.com/offline-labs/gocheckout@v0.0.2
 
 COPY etc/group /etc/group

ops/devcontainer/start.sh

@@ -10,4 +10,5 @@ sudo docker run --rm -it \
     -v /memory:/memory \
     --workdir /code \
     --net host \
+    --name gas \
     gas

ops/test.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+go test -tags fts5 ./...

pkg/codegen/modelgenerate/ast_helpers.go

@@ -27,10 +27,18 @@ const (
 // we don't have to do that.
 var TrailingComments = map[ast.Node]string{}
 
-// mustCall wraps a call expression in Must(...), producing AST for Must(inner).
+// mustCall wraps a call expression in must.Get(...), producing AST for must.Get(inner).
 func mustCall(inner ast.Expr) *ast.CallExpr {
 	return &ast.CallExpr{
-		Fun:  ast.NewIdent("Must"),
+		Fun:  &ast.SelectorExpr{X: ast.NewIdent("must"), Sel: ast.NewIdent("Get")},
+		Args: []ast.Expr{inner},
+	}
+}
+
+// doCall wraps a call expression in must.Do(...), producing AST for must.Do(inner).
+func doCall(inner ast.Expr) *ast.CallExpr {
+	return &ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: ast.NewIdent("must"), Sel: ast.NewIdent("Do")},
 		Args: []ast.Expr{inner},
 	}
 }
@@ -73,7 +81,7 @@ func FprintWithComments(w io.Writer, file *ast.File) error {
 	fset = token.NewFileSet()
 	parsed, err := parser.ParseFile(fset, "", buf.Bytes(), parser.ParseComments)
 	if err != nil {
-		return fmt.Errorf("re-parsing pretty-print: %w", err)
+		return fmt.Errorf("re-parsing pretty-print: %w\n\n%s", err, buf.String())
 	}
 
 	// Parallel walk: apply TrailingComments from the side map.

pkg/codegen/modelgenerate/generate_model.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"go/ast"
 	"go/token"
+	"slices"
 	"strings"
 
 	"github.com/jinzhu/inflection"
@@ -23,7 +24,7 @@ var (
 )
 
 func SQLFieldsConstIdent(tbl schema.Table) *ast.Ident {
-	return ast.NewIdent(strings.ToLower(tbl.GoTypeName) + "SQLFields")
+	return ast.NewIdent(strings.ToLower(tbl.GoTypeName[:1]) + tbl.GoTypeName[1:] + "SQLFields")
 }
 
 // GoTypeForColumn returns a type expression for this column.
@@ -53,20 +54,48 @@ func GoTypeForColumn(c schema.Column) ast.Expr {
 	}
 }
 
-func PanicIfRowsAffected(tbl schema.Table) *ast.IfStmt {
-	return &ast.IfStmt{
-		Cond: &ast.BinaryExpr{
+// MustBeRowsAffected produces an AST for a `must.Be(...)` call asserting that exactly one row
+// was affected by the preceding statement, e.g.:
+//
+//	must.Be(must.Get(result.RowsAffected()) == 1, "%w: Food ID=%d", ErrNotInDB, f.ID)
+//
+// For "without rowid" tables, the message includes the table's primary key column(s) instead of ID.
+func MustBeRowsAffected(tbl schema.Table) *ast.ExprStmt {
+	pkParts := []string{}
+	pkArgs := []ast.Expr{}
+	if tbl.IsWithoutRowid {
+		for _, col := range tbl.PrimaryKeyColumns() {
+			verb := "%v"
+			if col.Type == "integer" || col.Type == "int" || col.IsNonCodeTableForeignKey() {
+				verb = "%d"
+			}
+			pkParts = append(pkParts, fmt.Sprintf("%s=%s", col.Name, verb))
+			pkArgs = append(pkArgs, &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent(col.GoFieldName())})
+		}
+	} else {
+		pkParts = append(pkParts, "ID=%d")
+		pkArgs = append(pkArgs, &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("ID")})
+	}
+
+	msg := fmt.Sprintf("%%w: %s %s", tbl.GoTypeName, strings.Join(pkParts, ", "))
+
+	args := append([]ast.Expr{
+		&ast.BinaryExpr{
 			X: mustCall(&ast.CallExpr{
 				Fun:  &ast.SelectorExpr{X: ast.NewIdent("result"), Sel: ast.NewIdent("RowsAffected")},
 				Args: []ast.Expr{},
 			}),
-			Op: token.NEQ,
+			Op: token.EQL,
 			Y:  &ast.BasicLit{Kind: token.INT, Value: "1"},
 		},
-		Body: &ast.BlockStmt{List: []ast.Stmt{
-			&ast.ExprStmt{X: &ast.CallExpr{Fun: ast.NewIdent("panic"), Args: []ast.Expr{ast.NewIdent(tbl.VarName)}}},
-		}},
-	}
+		&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", msg)},
+		ast.NewIdent("ErrNotInDB"),
+	}, pkArgs...)
+
+	return &ast.ExprStmt{X: &ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: ast.NewIdent("must"), Sel: ast.NewIdent("Be")},
+		Args: args,
+	}}
 }
 
 // ---------------
@@ -161,79 +190,92 @@ func buildFKCheckLambda(tbl schema.Table) (*ast.AssignStmt, bool) {
 							structFieldName := col.GoFieldName()
 							structField := &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent(structFieldName)}
 
-							if col.IsNonCodeTableForeignKey() {
-								// Real foreign key; look up referent by ID to see if it exists
-								ret = append(ret, &ast.IfStmt{
-									Init: &ast.AssignStmt{
-										Lhs: []ast.Expr{ast.NewIdent("_"), ast.NewIdent("err")},
-										Tok: token.DEFINE,
-										Rhs: []ast.Expr{
-											&ast.CallExpr{
-												Fun:  &ast.SelectorExpr{X: ast.NewIdent("db"), Sel: ast.NewIdent(getByIDFuncName(col.ForeignKeyTargetTable))},
-												Args: []ast.Expr{structField},
+							ret = append(ret, func() ast.Stmt {
+								// Wrap nullable FKs in "if a.val != 0 { ... }"
+								wrap := func(input ast.Stmt) ast.Stmt {
+									if col.IsNullableForeignKey() {
+										return &ast.IfStmt{
+											Cond: &ast.BinaryExpr{X: structField, Op: token.NEQ, Y: &ast.BasicLit{Kind: token.INT, Value: "0"}},
+											Body: &ast.BlockStmt{List: []ast.Stmt{input}},
+										}
+									} else {
+										return input
+									}
+								}
+								if col.IsNonCodeTableForeignKey() {
+									// Real foreign key; look up referent by ID to see if it exists
+									return wrap(&ast.IfStmt{
+										Init: &ast.AssignStmt{
+											Lhs: []ast.Expr{ast.NewIdent("_"), ast.NewIdent("err")},
+											Tok: token.DEFINE,
+											Rhs: []ast.Expr{
+												&ast.CallExpr{
+													Fun:  &ast.SelectorExpr{X: ast.NewIdent("db"), Sel: ast.NewIdent(getByIDFuncName(col.ForeignKeyTargetTable))},
+													Args: []ast.Expr{structField},
+												},
 											},
 										},
-									},
-									Cond: &ast.CallExpr{
-										Fun:  &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")},
-										Args: []ast.Expr{ast.NewIdent("err"), ast.NewIdent("ErrNotInDB")},
-									},
-									Body: &ast.BlockStmt{
-										List: []ast.Stmt{
-											&ast.ReturnStmt{
-												Results: []ast.Expr{
-													&ast.CallExpr{
-														Fun: ast.NewIdent("NewForeignKeyError"),
-														Args: []ast.Expr{
-															&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", structFieldName)},
-															&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", col.ForeignKeyTargetTable)},
-															structField,
+										Cond: &ast.CallExpr{
+											Fun:  &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")},
+											Args: []ast.Expr{ast.NewIdent("err"), ast.NewIdent("ErrNotInDB")},
+										},
+										Body: &ast.BlockStmt{
+											List: []ast.Stmt{
+												&ast.ReturnStmt{
+													Results: []ast.Expr{
+														&ast.CallExpr{
+															Fun: ast.NewIdent("NewForeignKeyError"),
+															Args: []ast.Expr{
+																&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", structFieldName)},
+																&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", col.ForeignKeyTargetTable)},
+																structField,
+															},
 														},
 													},
 												},
 											},
 										},
-									},
-								})
-							} else {
-								// Code table value.  Query the table to see if it exists
-								ret = append(ret, &ast.IfStmt{
-									Init: &ast.AssignStmt{
-										Lhs: []ast.Expr{ast.NewIdent("err")},
-										Tok: token.DEFINE,
-										Rhs: []ast.Expr{
-											&ast.CallExpr{
-												Fun: &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Get")},
-												Args: []ast.Expr{
-													&ast.CallExpr{Fun: ast.NewIdent("new"), Args: []ast.Expr{ast.NewIdent("int")}},
-													&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`select 1 from %s where rowid = ?`", col.ForeignKeyTargetTable)},
-													structField,
+									})
+								} else {
+									// Code table value.  Query the table to see if it exists
+									return wrap(&ast.IfStmt{
+										Init: &ast.AssignStmt{
+											Lhs: []ast.Expr{ast.NewIdent("err")},
+											Tok: token.DEFINE,
+											Rhs: []ast.Expr{
+												&ast.CallExpr{
+													Fun: &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Get")},
+													Args: []ast.Expr{
+														&ast.CallExpr{Fun: ast.NewIdent("new"), Args: []ast.Expr{ast.NewIdent("int")}},
+														&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`select 1 from %s where rowid = ?`", col.ForeignKeyTargetTable)},
+														structField,
+													},
 												},
 											},
 										},
-									},
-									Cond: &ast.CallExpr{
-										Fun:  &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")},
-										Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}},
-									},
-									Body: &ast.BlockStmt{
-										List: []ast.Stmt{
-											&ast.ReturnStmt{
-												Results: []ast.Expr{
-													&ast.CallExpr{
-														Fun: ast.NewIdent("NewForeignKeyError"),
-														Args: []ast.Expr{
-															&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", structFieldName)},
-															&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", col.ForeignKeyTargetTable)},
-															structField,
+										Cond: &ast.CallExpr{
+											Fun:  &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")},
+											Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}},
+										},
+										Body: &ast.BlockStmt{
+											List: []ast.Stmt{
+												&ast.ReturnStmt{
+													Results: []ast.Expr{
+														&ast.CallExpr{
+															Fun: ast.NewIdent("NewForeignKeyError"),
+															Args: []ast.Expr{
+																&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", structFieldName)},
+																&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", col.ForeignKeyTargetTable)},
+																structField,
+															},
 														},
 													},
 												},
 											},
 										},
-									},
-								})
-							}
+									})
+								}
+							}())
 						}
 						// final return nil
 						ret = append(ret, &ast.ReturnStmt{Results: []ast.Expr{ast.NewIdent("nil")}})
@@ -255,7 +297,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 
 	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
 
-	// Assemble data for building SQL "insert" and "update" strings
+	// Assemble SQL "insert" string
 	for _, col := range tbl.Columns {
 		if col.Name == "rowid" {
 			continue
@@ -266,19 +308,20 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 			val = fmt.Sprintf("nullif(%s, 0)", val)
 		}
 		insertVals = append(insertVals, val)
-		// created_at should not be updated after creation
-		if col.Name == "created_at" && hasCreatedAt {
-			continue
-		}
-		if !col.IsPrimaryKey { // Don't try to update primary key columns (mainly for w/o rowid tables)
-			updatePairs = append(updatePairs, col.Name+"="+val)
-		}
 	}
 	insertStmt := fmt.Sprintf("\n\t\t    insert into %s (%s)\n\t\t         values (%s)\n\t\t",
 		tbl.TableName,
 		strings.Join(insertCols, ", "),
 		strings.Join(insertVals, ", "),
 	)
+	// ...and "update" string
+	for _, col := range tbl.GetUpdateableColumns() {
+		val := ":" + col.Name
+		if col.IsNullableForeignKey() {
+			val = fmt.Sprintf("nullif(%s, 0)", val)
+		}
+		updatePairs = append(updatePairs, col.Name+"="+val)
+	}
 	updateStmt := fmt.Sprintf("\n\t\t    update %s\n\t\t       set %s\n\t\t     where rowid = :rowid\n\t\t",
 		tbl.TableName,
 		strings.Join(updatePairs, ",\n\t\t           "),
@@ -320,7 +363,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 					},
 				}
 				if !hasFks {
-					// No foreign key checking needed; just use `Must` for brevity
+					// No foreign key checking needed; just use `must.Get` for brevity
 					return []ast.Stmt{&ast.AssignStmt{
 						Lhs: []ast.Expr{ast.NewIdent("result")},
 						Tok: token.DEFINE,
@@ -386,8 +429,26 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 			}
 
 			if tbl.IsWithoutRowid {
+				if hasCreatedAt {
+					// Auto-timestamps: created_at.  Don't overwrite existing timestamps (e.g., data import / migrations)
+					ret = append(ret, &ast.IfStmt{
+						Cond: &ast.CallExpr{Fun: &ast.SelectorExpr{
+							X:   &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")},
+							Sel: ast.NewIdent("IsZero"),
+						}},
+						Body: &ast.BlockStmt{
+							List: []ast.Stmt{
+								&ast.AssignStmt{
+									Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")}},
+									Tok: token.ASSIGN,
+									Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+								},
+							},
+						},
+					})
+				}
 				ret = append(ret, namedExecStmt(upsertStmt)...)
-				ret = append(ret, PanicIfRowsAffected(tbl))
+				ret = append(ret, MustBeRowsAffected(tbl))
 			} else {
 				// if item.ID == 0 {...} else {...}
 				ret = append(ret, &ast.IfStmt{
@@ -403,10 +464,21 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 								ret1 := []ast.Stmt{Comment("Do create")}
 								if hasCreatedAt {
 									// Auto-timestamps: created_at
-									ret1 = append(ret1, &ast.AssignStmt{
-										Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")}},
-										Tok: token.ASSIGN,
-										Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+									ret1 = append(ret1, &ast.IfStmt{
+										// Don't overwrite existing timestamps.  This is useful for various reasons, e.g., data import / migrations
+										Cond: &ast.CallExpr{Fun: &ast.SelectorExpr{
+											X:   &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")},
+											Sel: ast.NewIdent("IsZero"),
+										}},
+										Body: &ast.BlockStmt{
+											List: []ast.Stmt{
+												&ast.AssignStmt{
+													Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")}},
+													Tok: token.ASSIGN,
+													Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+												},
+											},
+										},
 									})
 								}
 								return append(ret1, namedExecStmt(insertStmt)...)
@@ -430,7 +502,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 							[]ast.Stmt{Comment("Do update")},
 							append(
 								namedExecStmt(updateStmt),
-								PanicIfRowsAffected(tbl),
+								MustBeRowsAffected(tbl),
 							)...,
 						),
 					},
@@ -444,11 +516,16 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 		}(),
 	}
 
+	docLines := []*ast.Comment{
+		{Text: fmt.Sprintf("// Save%s creates or updates a %s in the database.", tbl.GoTypeName, tbl.GoTypeName)},
+	}
+	if tbl.IsWithoutRowid {
+		docLines = append(docLines, &ast.Comment{Text: "// If a row with the same key already exists, it will be updated; otherwise it will be created."})
+	} else {
+		docLines = append(docLines, &ast.Comment{Text: "// If the item doesn't exist (has no ID set), it will create it; otherwise it will do an update."})
+	}
 	funcDecl := &ast.FuncDecl{
-		Doc: &ast.CommentGroup{List: []*ast.Comment{
-			{Text: fmt.Sprintf("// Save%s creates or updates a %s in the database.", tbl.GoTypeName, tbl.GoTypeName)},
-			{Text: "// If the item doesn't exist (has no ID set), it will create it; otherwise it will do an update."},
-		}},
+		Doc:  &ast.CommentGroup{List: docLines},
 		Recv: dbRecv,
 		Name: ast.NewIdent("Save" + tbl.GoTypeName),
 		Type: &ast.FuncType{
@@ -469,15 +546,50 @@ func getByIDFuncName(tblname string) string {
 	return "Get" + schema.TypenameFromTablename(tblname) + "ByID"
 }
 
+// paramNamesFor picks parameter identifiers for a `Get...By()` function's columns.
+// A single column always uses the short GoVarName() form (e.g. "name").  For multiple
+// columns, GoVarName() is preferred for readability, but if two or more of the given
+// columns would produce the same short name (e.g. two foreign keys that both abbreviate
+// to "uID"), the longer, unambiguous LongGoVarName() form is used for all of them instead,
+// since a collision there would produce invalid (duplicate-parameter) Go code.
+func paramNamesFor(cols []schema.Column) []string {
+	names := make([]string, len(cols))
+	if len(cols) == 1 {
+		names[0] = cols[0].GoVarName()
+		return names
+	}
+
+	hasConflict := false
+	for i, c := range cols {
+		names[i] = c.GoVarName()
+		if slices.Contains(names[:i], names[i]) {
+			hasConflict = true
+			break
+		}
+	}
+	if !hasConflict {
+		return names
+	}
+	for i, c := range cols {
+		names[i] = c.LongGoVarName()
+	}
+	return names
+}
+
+// GenerateGetItemBy produces an AST for a `GetXyzByCol1AndCol2...()` function that returns
+// the single item matching an exact-match lookup over the given columns (or ErrNotInDB).
+// Used for unique indexes (single- or multi-column) and for "without rowid" tables' primary keys.
 func GenerateGetItemBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
+	paramNames := paramNamesFor(cols)
+
 	colNames := []string{}
 	funcNameSuffix := []string{}
 	funcParams := &ast.FieldList{List: []*ast.Field{}}
 	sqlParams := []ast.Expr{}
-	for _, col := range cols {
-		funcParam := ast.NewIdent(col.LongGoVarName())
+	for i, col := range cols {
+		funcParam := ast.NewIdent(paramNames[i])
 		funcParams.List = append(funcParams.List, &ast.Field{Names: []*ast.Ident{funcParam}, Type: GoTypeForColumn(col)})
-		colNames = append(colNames, fmt.Sprintf("%s = :%s", col.Name, col.Name))
+		colNames = append(colNames, fmt.Sprintf("%s = ?", col.Name))
 		funcNameSuffix = append(funcNameSuffix, col.GoFieldName())
 		sqlParams = append(sqlParams, funcParam)
 	}
@@ -489,7 +601,7 @@ func GenerateGetItemBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
 			Y:  SQLFieldsConstIdent(tbl),
 		},
 		Op: token.ADD,
-		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s = ?\n\t`", tbl.TableName, strings.Join(colNames, " and "))},
+		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s\n\t`", tbl.TableName, strings.Join(colNames, " and "))},
 	}
 
 	return &ast.FuncDecl{
@@ -515,7 +627,8 @@ func GenerateGetItemBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
 				&ast.IfStmt{
 					Cond: &ast.CallExpr{
 						Fun:  &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")},
-						Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}}},
+						Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}},
+					},
 					Body: &ast.BlockStmt{List: []ast.Stmt{&ast.ReturnStmt{Results: []ast.Expr{&ast.CompositeLit{Type: ast.NewIdent(tbl.GoTypeName)}, ast.NewIdent("ErrNotInDB")}}}},
 				},
 				&ast.ReturnStmt{},
@@ -564,10 +677,33 @@ func GenerateGetItemByIDFunc(tbl schema.Table) *ast.FuncDecl {
 	}
 }
 
-// GenerateGetItemByUniqColFunc produces an AST for the `GetXyzByID()` function.
-// E.g., a table with `table.TypeName = "foods"` will produce a "GetFoodByID()" function.
+// GenerateGetItemByUniqColFunc produces an AST for the `GetXyzByCol()` function, for a unique
+// index on a single column.
+// E.g., a table with `table.TypeName = "foods"` will produce a "GetFoodByName()" function.
 func GenerateGetItemByUniqColFunc(tbl schema.Table, col schema.Column) *ast.FuncDecl {
-	// Use the xyzSQLFields constant in the select query
+	return GenerateGetItemBy(tbl, []schema.Column{col})
+}
+
+// GenerateGetItemsBy produces an AST for a `GetXyzsByCol1AndCol2...()` function that returns
+// all items matching an exact-match lookup over the given columns.  Used for non-unique
+// indexes (single- or multi-column).
+// E.g., a table with `table.TableName = "foods"` and a non-unique index on "category" will
+// produce a "GetFoodsByCategory(category string) []Food" function.
+func GenerateGetItemsBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
+	paramNames := paramNamesFor(cols)
+
+	colNames := []string{}
+	funcNameSuffix := []string{}
+	funcParams := &ast.FieldList{List: []*ast.Field{}}
+	sqlParams := []ast.Expr{}
+	for i, col := range cols {
+		funcParam := ast.NewIdent(paramNames[i])
+		funcParams.List = append(funcParams.List, &ast.Field{Names: []*ast.Ident{funcParam}, Type: GoTypeForColumn(col)})
+		colNames = append(colNames, fmt.Sprintf("%s = ?", col.Name))
+		funcNameSuffix = append(funcNameSuffix, col.GoFieldName())
+		sqlParams = append(sqlParams, funcParam)
+	}
+
 	selectExpr := &ast.BinaryExpr{
 		X: &ast.BinaryExpr{
 			X:  &ast.BasicLit{Kind: token.STRING, Value: "`\n\t    select `"},
@@ -575,40 +711,40 @@ func GenerateGetItemByUniqColFunc(tbl schema.Table, col schema.Column) *ast.Func
 			Y:  SQLFieldsConstIdent(tbl),
 		},
 		Op: token.ADD,
-		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s = ?\n\t`", tbl.TableName, col.Name)},
+		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s\n\t`", tbl.TableName, strings.Join(colNames, " and "))},
 	}
 
-	param := ast.NewIdent(col.GoVarName())
+	selectCall := doCall(&ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Select")},
+		Args: append([]ast.Expr{&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")}, selectExpr}, sqlParams...),
+	})
 
 	return &ast.FuncDecl{
 		Recv: dbRecv,
-		Name: ast.NewIdent("Get" + schema.TypenameFromTablename(tbl.TableName) + "By" + col.GoFieldName()),
+		Name: ast.NewIdent("Get" + inflection.Plural(schema.TypenameFromTablename(tbl.TableName)) + "By" + strings.Join(funcNameSuffix, "And")),
 		Type: &ast.FuncType{
-			Params: &ast.FieldList{List: []*ast.Field{
-				{Names: []*ast.Ident{param}, Type: GoTypeForColumn(col)},
-			}},
+			Params: funcParams,
 			Results: &ast.FieldList{List: []*ast.Field{
-				{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: ast.NewIdent(tbl.GoTypeName)},
-				{Names: []*ast.Ident{ast.NewIdent("err")}, Type: ast.NewIdent("error")},
+				{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: &ast.ArrayType{Elt: ast.NewIdent(tbl.GoTypeName)}},
 			}},
 		},
 		Body: &ast.BlockStmt{
 			List: []ast.Stmt{
-				&ast.AssignStmt{
-					Lhs: []ast.Expr{ast.NewIdent("err")},
-					Tok: token.ASSIGN,
-					Rhs: []ast.Expr{&ast.CallExpr{Fun: &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Get")}, Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")}, selectExpr, param}}},
-				},
-				&ast.IfStmt{
-					Cond: &ast.CallExpr{Fun: &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")}, Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}}},
-					Body: &ast.BlockStmt{List: []ast.Stmt{&ast.ReturnStmt{Results: []ast.Expr{&ast.CompositeLit{Type: ast.NewIdent(tbl.GoTypeName)}, ast.NewIdent("ErrNotInDB")}}}},
-				},
+				&ast.ExprStmt{X: selectCall},
 				&ast.ReturnStmt{},
 			},
 		},
 	}
 }
 
+// GenerateGetItemsByColFunc produces an AST for the `GetXyzsByCol()` function, for a non-unique
+// index on a single column.
+// E.g., a table with `table.TableName = "foods"` and a non-unique index on "category" will
+// produce a "GetFoodsByCategory(category string) []Food" function.
+func GenerateGetItemsByColFunc(tbl schema.Table, col schema.Column) *ast.FuncDecl {
+	return GenerateGetItemsBy(tbl, []schema.Column{col})
+}
+
 // GenerateGetAllItemsFunc produces an AST for the `GetAllXyzs()` function.
 // E.g., a table with `table.TypeName = "foods"` will produce a "GetAllFoods()" function.
 func GenerateGetAllItemsFunc(tbl schema.Table) *ast.FuncDecl {
@@ -617,29 +753,24 @@ func GenerateGetAllItemsFunc(tbl schema.Table) *ast.FuncDecl {
 		{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: &ast.ArrayType{Elt: ast.NewIdent(tbl.GoTypeName)}},
 	}}
 
-	selectCall := &ast.CallExpr{
-		Fun: ast.NewIdent("PanicIf"),
+	selectCall := doCall(&ast.CallExpr{
+		Fun: &ast.SelectorExpr{
+			X:   dbDB,
+			Sel: ast.NewIdent("Select"),
+		},
 		Args: []ast.Expr{
-			&ast.CallExpr{
-				Fun: &ast.SelectorExpr{
-					X:   dbDB,
-					Sel: ast.NewIdent("Select"),
-				},
-				Args: []ast.Expr{
-					&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")},
-					&ast.BinaryExpr{
-						X: &ast.BinaryExpr{
-							X:  &ast.BasicLit{Kind: token.STRING, Value: "`select `"},
-							Op: token.ADD,
-							Y:  SQLFieldsConstIdent(tbl),
-						},
-						Op: token.ADD,
-						Y:  &ast.BasicLit{Kind: token.STRING, Value: "` from " + tbl.TableName + "`"},
-					},
+			&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")},
+			&ast.BinaryExpr{
+				X: &ast.BinaryExpr{
+					X:  &ast.BasicLit{Kind: token.STRING, Value: "`select `"},
+					Op: token.ADD,
+					Y:  SQLFieldsConstIdent(tbl),
 				},
+				Op: token.ADD,
+				Y:  &ast.BasicLit{Kind: token.STRING, Value: "` from " + tbl.TableName + "`"},
 			},
 		},
-	}
+	})
 
 	funcBody := &ast.BlockStmt{
 		List: []ast.Stmt{
@@ -682,7 +813,7 @@ func GenerateDeleteItemFunc(tbl schema.Table) *ast.FuncDecl {
 					},
 				})},
 			},
-			PanicIfRowsAffected(tbl),
+			MustBeRowsAffected(tbl),
 		},
 	}
 
@@ -698,6 +829,66 @@ func GenerateDeleteItemFunc(tbl schema.Table) *ast.FuncDecl {
 	return funcDecl
 }
 
+// GenerateSoftDeleteItemFunc produces an AST for the `SoftDeleteXyz()` function, which is only
+// generated for tables that have both an "is_deleted" and a "deleted_at" column.
+// E.g., a table with `table.TypeName = "foods"` will produce a "SoftDeleteFood()" function.
+func GenerateSoftDeleteItemFunc(tbl schema.Table) *ast.FuncDecl {
+	whereClauses := []string{}
+	for _, c := range tbl.PrimaryKeyColumns() {
+		whereClauses = append(whereClauses, fmt.Sprintf("%s = :%s", c.Name, c.Name))
+	}
+	setPairs := []string{"is_deleted = :is_deleted", "deleted_at = :deleted_at"}
+
+	updateStmt := fmt.Sprintf("\n\t    update %s\n\t       set %s\n\t     where %s\n\t",
+		tbl.TableName,
+		strings.Join(setPairs, ",\n\t           "),
+		strings.Join(whereClauses, " and "),
+	)
+
+	funcBody := &ast.BlockStmt{
+		List: []ast.Stmt{
+			// item.IsDeleted = true
+			&ast.AssignStmt{
+				Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent(tbl.GetColumnByName("is_deleted").GoFieldName())}},
+				Tok: token.ASSIGN,
+				Rhs: []ast.Expr{ast.NewIdent("true")},
+			},
+			// item.DeletedAt = TimestampNow()
+			&ast.AssignStmt{
+				Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent(tbl.GetColumnByName("deleted_at").GoFieldName())}},
+				Tok: token.ASSIGN,
+				Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+			},
+			// result := must.Get(db.DB.NamedExec(...))
+			&ast.AssignStmt{
+				Lhs: []ast.Expr{ast.NewIdent("result")},
+				Tok: token.DEFINE,
+				Rhs: []ast.Expr{mustCall(&ast.CallExpr{
+					Fun: &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("NamedExec")},
+					Args: []ast.Expr{
+						&ast.BasicLit{Kind: token.STRING, Value: "`" + updateStmt + "`"},
+						ast.NewIdent(tbl.VarName),
+					},
+				})},
+			},
+			MustBeRowsAffected(tbl),
+		},
+	}
+
+	return &ast.FuncDecl{
+		Doc: &ast.CommentGroup{List: []*ast.Comment{
+			{Text: fmt.Sprintf("// SoftDelete%s sets deleted-at and marks the item as deleted.", tbl.GoTypeName)},
+		}},
+		Recv: dbRecv,
+		Name: ast.NewIdent("SoftDelete" + tbl.GoTypeName),
+		Type: &ast.FuncType{Params: &ast.FieldList{List: []*ast.Field{{
+			Names: []*ast.Ident{ast.NewIdent(tbl.VarName)},
+			Type:  &ast.StarExpr{X: ast.NewIdent(tbl.GoTypeName)},
+		}}}, Results: nil},
+		Body: funcBody,
+	}
+}
+
 // GenerateSQLFieldsConst produces an AST for the `const xyzSQLFields = ...` string.
 func GenerateSQLFieldsConst(tbl schema.Table) *ast.GenDecl {
 	columns := make([]string, 0, len(tbl.Columns))

pkg/codegen/modelgenerate/generate_testfile.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"go/ast"
 	"go/token"
+	"slices"
+	"strings"
 
 	"github.com/jinzhu/inflection"
 
@@ -11,6 +13,77 @@ import (
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
+// SampleValue returns a deterministic value of the appropriate type for the given column.
+func SampleValue(c pkgschema.Column, offset int) ast.Expr {
+	switch c.Type {
+	case "integer", "int":
+		if strings.HasPrefix(c.Name, "is_") || strings.HasPrefix(c.Name, "has_") {
+			// Boolean case
+			if offset%2 == 0 {
+				return ast.NewIdent("false")
+			}
+			return ast.NewIdent("true")
+		} else if strings.HasSuffix(c.Name, "_at") {
+			// Timestamp case
+			return &ast.CallExpr{
+				Fun: ast.NewIdent("TimestampFromUnix"),
+				Args: []ast.Expr{
+					&ast.BasicLit{Kind: token.INT, Value: fmt.Sprintf("%d", 10000+offset)},
+				},
+			}
+		} else {
+			// Regular integer case
+			return &ast.BasicLit{Kind: token.INT, Value: fmt.Sprintf("%d", 10+offset)}
+		}
+	case "text":
+		if offset == 0 {
+			return &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", "asdf")}
+		}
+		return &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", fmt.Sprintf("asdf%d", offset))}
+	case "real":
+		return &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprintf("%.2f", 1.23+float64(offset))}
+	case "blob":
+		return &ast.CompositeLit{
+			Type: &ast.ArrayType{
+				Elt: ast.NewIdent("byte"),
+			},
+			Elts: func() []ast.Expr {
+				ret := []ast.Expr{
+					&ast.BasicLit{Kind: token.INT, Value: "72"},  // 'H'
+					&ast.BasicLit{Kind: token.INT, Value: "105"}, // 'i'
+					&ast.BasicLit{Kind: token.INT, Value: "33"},  // '!'
+				}
+				for range offset {
+					ret = append(ret,
+						&ast.BasicLit{Kind: token.INT, Value: "33"}, // '!'
+					)
+				}
+				return ret
+			}(),
+		}
+	default:
+		panic("Unrecognized sqlite column type: " + c.Type)
+	}
+}
+
+// UpdateTestFields returns the columns for which the test generator should assign its own
+// sample values in MakeXyz() and the create/update test. It starts with Table.GetUpdateableColumns()
+// and removes fields the generated test should not assign directly: foreign keys and auto-managed
+// updated_at.
+func UpdateTestFields(tbl pkgschema.Table) (ret []pkgschema.Column) {
+	_, hasUpdatedAt := tbl.HasAutoTimestamps()
+	for _, c := range tbl.GetUpdateableColumns() {
+		if c.IsForeignKey {
+			continue
+		}
+		if c.Name == "updated_at" && hasUpdatedAt {
+			continue
+		}
+		ret = append(ret, c)
+	}
+	return
+}
+
 // GenerateModelTestAST produces an AST for a starter test file for a given model.
 func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodName string) *ast.File {
 	packageName := "db"
@@ -18,11 +91,57 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 
 	makeHelperName := ast.NewIdent("Make" + tbl.GoTypeName)
 
+	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
+	updateTestFields := UpdateTestFields(tbl)
+	uniqueColumns := map[string]bool{}
+	for _, index := range schema.Indexes {
+		if index.TableName != tbl.TableName || !index.IsUnique {
+			continue
+		}
+		for _, columnName := range index.Columns {
+			uniqueColumns[columnName] = true
+		}
+	}
+	hasRandomUniqueField := false
+	for _, c := range updateTestFields {
+		if uniqueColumns[c.Name] {
+			hasRandomUniqueField = true
+			break
+		}
+	}
+	requiredForeignKeys := []pkgschema.Column{}
+	for _, c := range tbl.Columns {
+		// Only ordinary object foreign keys use a distinct TargetObjectID Go type;
+		// code-table foreign keys retain their underlying SQLite type in the generated model.
+		if c.IsNotNull && c.IsNonCodeTableForeignKey() {
+			requiredForeignKeys = append(requiredForeignKeys, c)
+		}
+	}
+	requiredForeignKeyParamNames := paramNamesFor(requiredForeignKeys)
+
+	// Calls made by this generated test do not create related objects themselves. Pass a
+	// zero ID so the generated test remains syntactically valid; callers of MakeXyz provide
+	// IDs of the related objects they create.
+	makeItemArgs := func() (ret []ast.Expr) {
+		for range requiredForeignKeys {
+			ret = append(ret, &ast.BasicLit{Kind: token.INT, Value: "0"})
+		}
+		return
+	}()
+
 	// func MakeItem() Item { return Item{} }
 	makeItemFunc := &ast.FuncDecl{
 		Name: makeHelperName,
 		Type: &ast.FuncType{
-			Params: &ast.FieldList{},
+			Params: &ast.FieldList{List: func() (ret []*ast.Field) {
+				for i, c := range requiredForeignKeys {
+					ret = append(ret, &ast.Field{
+						Names: []*ast.Ident{ast.NewIdent(requiredForeignKeyParamNames[i])},
+						Type:  GoTypeForColumn(c),
+					})
+				}
+				return
+			}()},
 			Results: &ast.FieldList{
 				List: []*ast.Field{
 					{Type: ast.NewIdent(tbl.GoTypeName)},
@@ -30,44 +149,102 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 			},
 		},
 		Body: &ast.BlockStmt{
-			List: []ast.Stmt{
-				&ast.ReturnStmt{
-					Results: []ast.Expr{
-						&ast.CompositeLit{
-							Type: ast.NewIdent(tbl.GoTypeName),
-							Elts: []ast.Expr{
-								&ast.KeyValueExpr{
-									Key: ast.NewIdent("Data"),
-									Value: &ast.CompositeLit{
-										Type: &ast.ArrayType{
-											Elt: ast.NewIdent("byte"),
-										},
-										Elts: []ast.Expr{},
-									},
-								},
-								&ast.KeyValueExpr{
-									Key: ast.NewIdent("Description"),
-									Value: &ast.BasicLit{
-										Kind:  token.STRING,
-										Value: `""`,
-									},
-								},
+			List: append(
+				func() []ast.Stmt {
+					if !hasRandomUniqueField {
+						return nil
+					}
+					return []ast.Stmt{&ast.AssignStmt{
+						Lhs: []ast.Expr{ast.NewIdent("id")},
+						Tok: token.DEFINE,
+						Rhs: []ast.Expr{&ast.CallExpr{Fun: &ast.SelectorExpr{X: ast.NewIdent("rand"), Sel: ast.NewIdent("Int")}}},
+					}}
+				}(),
+				[]ast.Stmt{
+					&ast.ReturnStmt{
+						Results: []ast.Expr{
+							&ast.CompositeLit{
+								Type: ast.NewIdent(tbl.GoTypeName),
+								Elts: func() (ret []ast.Expr) {
+									// `UpdateTestFields()` skips foreign keys, so this will not cause duplicates
+									for i, c := range requiredForeignKeys {
+										ret = append(ret, &ast.KeyValueExpr{
+											Key:   ast.NewIdent(c.GoFieldName()),
+											Value: ast.NewIdent(requiredForeignKeyParamNames[i]),
+										})
+									}
+									for _, c := range updateTestFields {
+										value := SampleValue(c, 0)
+										if uniqueColumns[c.Name] {
+											switch c.Type {
+											case "integer", "int":
+												value = ast.NewIdent("id")
+											case "text":
+												value = &ast.CallExpr{
+													Fun: &ast.SelectorExpr{X: ast.NewIdent("fmt"), Sel: ast.NewIdent("Sprintf")},
+													Args: []ast.Expr{
+														&ast.BasicLit{Kind: token.STRING, Value: `"%s-%d"`},
+														SampleValue(c, 0),
+														ast.NewIdent("id"),
+													},
+												}
+											case "blob":
+												value = &ast.CallExpr{
+													Fun: &ast.ArrayType{Elt: ast.NewIdent("byte")},
+													Args: []ast.Expr{&ast.CallExpr{
+														Fun: &ast.SelectorExpr{X: ast.NewIdent("fmt"), Sel: ast.NewIdent("Sprintf")},
+														Args: []ast.Expr{
+															&ast.BasicLit{Kind: token.STRING, Value: `"%s-%d"`},
+															&ast.CallExpr{Fun: ast.NewIdent("string"), Args: []ast.Expr{SampleValue(c, 0)}},
+															ast.NewIdent("id"),
+														},
+													}},
+												}
+											}
+										}
+										ret = append(ret, &ast.KeyValueExpr{
+											Key:   ast.NewIdent(c.GoFieldName()),
+											Value: value,
+										})
+									}
+									return
+								}(),
 							},
 						},
 					},
-				},
-			},
+				}...,
+			),
 		},
 	}
 
 	testObj := ast.NewIdent(textutils.CamelToPascal(tbl.GoTypeName))
 	testObj2 := ast.NewIdent(textutils.CamelToPascal(tbl.GoTypeName) + "2")
-	fieldName := ast.NewIdent("Description") // TODO
-	description1 := "an item"
-	description2 := "a big item"
 	testDB := ast.NewIdent("TestDB")
 
-	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
+	// getItemByPKCall builds a call to this table's primary-key getter (e.g. `TestDB.GetItemByID(item.ID)`,
+	// or `TestDB.GetItemByColAAndColB(item.ColA, item.ColB)` for "without rowid" tables with a
+	// compound primary key), matching whatever GenerateGetItemByIDFunc/GenerateGetItemBy generated.
+	getItemByPKCall := func(obj *ast.Ident) *ast.CallExpr {
+		if !tbl.IsWithoutRowid {
+			// Normal rowid table: use GetXyzByID
+			return &ast.CallExpr{
+				Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
+				Args: []ast.Expr{&ast.SelectorExpr{X: obj, Sel: ast.NewIdent("ID")}},
+			}
+		} else {
+			// "Without rowid" table: use the primary key "GetItemByBlahBlah" query func
+			funcNameSuffix := []string{}
+			args := []ast.Expr{}
+			for _, c := range tbl.PrimaryKeyColumns() {
+				funcNameSuffix = append(funcNameSuffix, c.GoFieldName())
+				args = append(args, &ast.SelectorExpr{X: obj, Sel: ast.NewIdent(c.GoFieldName())})
+			}
+			return &ast.CallExpr{
+				Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "By" + strings.Join(funcNameSuffix, "And"))},
+				Args: args,
+			}
+		}
+	}
 
 	makeDeepEqual := func(obj1 *ast.Ident, obj2 *ast.Ident) *ast.IfStmt {
 		return &ast.IfStmt{
@@ -147,7 +324,8 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 							Tok: map[bool]token.Token{true: token.DEFINE, false: token.ASSIGN}[isFirst],
 							Rhs: []ast.Expr{
 								&ast.CallExpr{
-									Fun: ast.NewIdent("Make" + tbl.GoTypeName),
+									Fun:  ast.NewIdent("Make" + tbl.GoTypeName),
+									Args: makeItemArgs,
 								},
 							},
 						},
@@ -234,25 +412,24 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					&ast.AssignStmt{
 						Lhs: []ast.Expr{testObj},
 						Tok: token.DEFINE,
-						Rhs: []ast.Expr{&ast.CallExpr{Fun: makeHelperName, Args: nil}},
+						Rhs: []ast.Expr{&ast.CallExpr{Fun: makeHelperName, Args: makeItemArgs}},
 					},
-					// item.Description = "an item"
-					&ast.AssignStmt{
+					// item.Description = <sample value, offset 1>
+					// ...one assignment per updatable field
+				}
+				for _, c := range updateTestFields {
+					stmts = append(stmts, &ast.AssignStmt{
 						Lhs: []ast.Expr{
 							&ast.SelectorExpr{
 								X:   testObj,
-								Sel: ast.NewIdent("Description"),
+								Sel: ast.NewIdent(c.GoFieldName()),
 							},
 						},
 						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{
-							&ast.BasicLit{
-								Kind:  token.STRING,
-								Value: fmt.Sprintf("%q", description1),
-							},
-						},
-					},
-
+						Rhs: []ast.Expr{SampleValue(c, 1)},
+					})
+				}
+				stmts = append(stmts,
 					// TestDB.SaveItem(&item), possibly with error check
 					&ast.ExprStmt{X: func() *ast.CallExpr {
 						mainExpr := &ast.CallExpr{
@@ -268,12 +445,14 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						}
 						return mainExpr
 					}()},
+				)
 
-					// require.NotZero(t, item.ID)
-					&ast.ExprStmt{X: &ast.CallExpr{
+				// require.NotZero(t, item.ID)
+				if !tbl.IsWithoutRowid { // non-rowid tables don't get an ID
+					stmts = append(stmts, &ast.ExprStmt{X: &ast.CallExpr{
 						Fun:  &ast.SelectorExpr{X: ast.NewIdent("require"), Sel: ast.NewIdent("NotZero")},
 						Args: []ast.Expr{ast.NewIdent("t"), &ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-					}},
+					}})
 				}
 
 				// After create: assert timestamps are set
@@ -288,50 +467,51 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					BlankLine(),
 					Comment("Load"),
 
-					// item2 := Must(TestDB.GetItemByID(item.ID))
+					// item2 := must.Get(TestDB.GetItemByID(item.ID))
 					&ast.AssignStmt{
 						Lhs: []ast.Expr{testObj2},
 						Tok: token.DEFINE,
-						Rhs: []ast.Expr{mustCall(&ast.CallExpr{
-							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
-							Args: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-						})},
+						Rhs: []ast.Expr{mustCall(getItemByPKCall(testObj))},
 					},
 
 					// if deep.Equal(...) {...}
 					makeDeepEqual(testObj, testObj2),
 				)
 
-				stmts = append(stmts,
-					BlankLine(),
-					Comment("Update"),
+				if len(tbl.GetUpdateableColumns()) > 0 { // Skip if no mutable fields
+					stmts = append(stmts,
+						BlankLine(),
+						Comment("Update"),
+					)
 
-					// item.Description = "a big item"
-					&ast.AssignStmt{
-						Lhs: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: fieldName}},
-						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", description2)}},
-					},
+					// item.Description = <sample value, offset 2>
+					// ...one assignment per updatable field
+					for _, c := range updateTestFields {
+						stmts = append(stmts, &ast.AssignStmt{
+							Lhs: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent(c.GoFieldName())}},
+							Tok: token.ASSIGN,
+							Rhs: []ast.Expr{SampleValue(c, 2)},
+						})
+					}
 
-					// TestDB.SaveItem(&item)
-					&ast.ExprStmt{X: &ast.CallExpr{
-						Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Save" + tbl.GoTypeName)},
-						Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: testObj}},
-					}},
+					stmts = append(stmts,
+						// TestDB.SaveItem(&item)
+						&ast.ExprStmt{X: &ast.CallExpr{
+							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Save" + tbl.GoTypeName)},
+							Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: testObj}},
+						}},
 
-					// item2 = Must(TestDB.GetItemByID(item.ID))
-					&ast.AssignStmt{
-						Lhs: []ast.Expr{testObj2},
-						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{mustCall(&ast.CallExpr{
-							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
-							Args: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-						})},
-					},
+						// item2 = must.Get(TestDB.GetItemByID(item.ID))
+						&ast.AssignStmt{
+							Lhs: []ast.Expr{testObj2},
+							Tok: token.ASSIGN,
+							Rhs: []ast.Expr{mustCall(getItemByPKCall(testObj))},
+						},
 
-					// if deep.Equal(...) {...}
-					makeDeepEqual(testObj, testObj2),
-				)
+						// if deep.Equal(...) {...}
+						makeDeepEqual(testObj, testObj2),
+					)
+				}
 
 				indexGets, hasIndexedGets := []ast.Stmt{
 					BlankLine(),
@@ -343,8 +523,21 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						// Skip indexes on other tables
 						continue
 					}
-					if index.IsUnique && len(index.Columns) == 1 {
-						col := tbl.GetColumnByName(index.Columns[0])
+					if slices.Contains(index.Columns, "") {
+						// Skip expression indexes; there's no way to resolve an expression to a real column
+						continue
+					}
+					cols := make([]pkgschema.Column, len(index.Columns))
+					nameParts := make([]string, len(index.Columns))
+					callArgs := make([]ast.Expr, len(index.Columns))
+					for i, colName := range index.Columns {
+						cols[i] = tbl.GetColumnByName(colName)
+						nameParts[i] = cols[i].GoFieldName()
+						callArgs[i] = &ast.SelectorExpr{X: testObj2, Sel: ast.NewIdent(cols[i].GoFieldName())}
+					}
+					funcNameSuffix := strings.Join(nameParts, "And")
+
+					if index.IsUnique {
 						indexGets = append(indexGets, []ast.Stmt{
 							// assert.Equal(t, item2, TestDB.GetItemByXYZ(...))
 							&ast.ExprStmt{X: &ast.CallExpr{ // TODO: what if just delete the "ExprStmt" wrapper?
@@ -354,16 +547,33 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 									testObj2,
 									mustCall(&ast.CallExpr{
 										Fun: &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent(
-											"Get" + pkgschema.TypenameFromTablename(tbl.TableName) + "By" + col.GoFieldName(),
+											"Get" + pkgschema.TypenameFromTablename(tbl.TableName) + "By" + funcNameSuffix,
 										)},
-										Args: []ast.Expr{&ast.SelectorExpr{X: testObj2, Sel: ast.NewIdent(col.GoFieldName())}},
+										Args: callArgs,
 									}),
 								},
 							}},
 						}...)
-						// decls = append(decls, modelgenerate.GenerateGetItemByUniqColFunc(table, table.GetColumnByName(index.Columns[0])))
-						hasIndexedGets = true
+					} else {
+						indexGets = append(indexGets, []ast.Stmt{
+							// assert.Contains(t, TestDB.GetItemsByXYZ(...), item2)
+							&ast.ExprStmt{X: &ast.CallExpr{
+								Fun: &ast.SelectorExpr{X: ast.NewIdent("assert"), Sel: ast.NewIdent("Contains")},
+								Args: []ast.Expr{
+									ast.NewIdent("t"),
+									&ast.CallExpr{
+										Fun: &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent(
+											"Get" + inflection.Plural(pkgschema.TypenameFromTablename(tbl.TableName)) +
+												"By" + funcNameSuffix,
+										)},
+										Args: callArgs,
+									},
+									testObj2,
+								},
+							}},
+						}...)
 					}
+					hasIndexedGets = true
 				}
 
 				if hasIndexedGets {
@@ -384,10 +594,7 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					&ast.AssignStmt{
 						Lhs: []ast.Expr{ast.NewIdent("_"), ast.NewIdent("err")},
 						Tok: token.DEFINE,
-						Rhs: []ast.Expr{&ast.CallExpr{
-							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
-							Args: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-						}},
+						Rhs: []ast.Expr{getItemByPKCall(testObj)},
 					},
 
 					// assert.ErrorIs(t, err, db.ErrNotInDB)
@@ -438,24 +645,33 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 		Decls: append([]ast.Decl{
 			&ast.GenDecl{
 				Tok: token.IMPORT,
-				Specs: []ast.Spec{
-					&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"testing"`}},
-					&ast.ImportSpec{
-						Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"`},
-						Name: ast.NewIdent("."),
-					},
-					&ast.ImportSpec{
-						Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"`},
-						Name: ast.NewIdent("."),
-					},
-					&ast.ImportSpec{
-						Path: &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf(`"%s/pkg/%s"`, gomodName, packageName)},
-						Name: ast.NewIdent("."),
-					},
-					&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"github.com/go-test/deep"`}},
-					&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"github.com/stretchr/testify/assert"`}},
-					&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"github.com/stretchr/testify/require"`}},
-				},
+				Specs: func() []ast.Spec {
+					specs := []ast.Spec{}
+					if hasRandomUniqueField {
+						specs = append(specs,
+							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"fmt"`}},
+							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"math/rand"`}},
+						)
+					}
+					specs = append(specs, []ast.Spec{
+						&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"testing"`}},
+						&ast.ImportSpec{
+							Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"`},
+							Name: ast.NewIdent("."),
+						},
+						&ast.ImportSpec{
+							Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"`},
+						},
+						&ast.ImportSpec{
+							Path: &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf(`"%s/pkg/%s"`, gomodName, packageName)},
+							Name: ast.NewIdent("."),
+						},
+						&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"github.com/go-test/deep"`}},
+						&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"github.com/stretchr/testify/assert"`}},
+						&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"github.com/stretchr/testify/require"`}},
+					}...)
+					return specs
+				}(),
 			},
 		}, testList...),
 	}

pkg/codegen/pkg.go

@@ -7,7 +7,7 @@ import (
 	"os/exec"
 	"text/template"
 
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 )
 
 //go:embed "tpl"
@@ -22,31 +22,31 @@ type PkgOpts struct {
 func InitPkg(opts PkgOpts) {
 	// Run `go mod init`
 	fmt.Printf("Running...  `go mod init %s`\n", opts.ModuleName)
-	PanicIf(exec.Command("go", "mod", "init", opts.ModuleName).Run())
+	must.Do(exec.Command("go", "mod", "init", opts.ModuleName).Run())
 
 	// Run `git init`, if required
 	if exec.Command("git", "status").Run() != nil {
 		// Not in a git repo yet; init one
 		fmt.Println("Running...  `git init`")
-		PanicIf(exec.Command("git", "init").Run())
+		must.Do(exec.Command("git", "init").Run())
 	}
 
 	// Create package structure
-	PanicIf(os.MkdirAll("pkg/db", 0o755))
-	PanicIf(os.MkdirAll("cmd", 0o755))
-	PanicIf(os.MkdirAll("doc", 0o755))
-	PanicIf(os.MkdirAll("sample_data", 0o755))
+	must.Do(os.MkdirAll("pkg/db", 0o755))
+	must.Do(os.MkdirAll("cmd", 0o755))
+	must.Do(os.MkdirAll("doc", 0o755))
+	must.Do(os.MkdirAll("sample_data", 0o755))
 
-	PanicIf(os.WriteFile("pkg/db/schema.sql", Must(tpl.ReadFile("tpl/schema.sql")), 0o664))
-	PanicIf(os.WriteFile("pkg/db/db.go", Must(tpl.ReadFile("tpl/db.go.tpl")), 0o664))
+	must.Do(os.WriteFile("pkg/db/schema.sql", must.Get(tpl.ReadFile("tpl/schema.sql")), 0o664))
+	must.Do(os.WriteFile("pkg/db/db.go", must.Get(tpl.ReadFile("tpl/db.go.tpl")), 0o664))
 
-	dbTest := Must(os.Create("pkg/db/db_test.go"))
-	defer MustClose(dbTest)
-	t := Must(template.ParseFS(tpl, "tpl/db_test.go.tpl"))
-	PanicIf(t.Execute(dbTest, opts))
+	dbTest := must.Get(os.Create("pkg/db/db_test.go"))
+	defer must.Close(dbTest)
+	t := must.Get(template.ParseFS(tpl, "tpl/db_test.go.tpl"))
+	must.Do(t.Execute(dbTest, opts))
 
-	PanicIf(os.WriteFile("sample_data/mount.sh", Must(tpl.ReadFile("tpl/mount.sh")), 0o775))
-	PanicIf(os.WriteFile("sample_data/reset.sh", Must(tpl.ReadFile("tpl/reset.sh")), 0o775))
+	must.Do(os.WriteFile("sample_data/mount.sh", must.Get(tpl.ReadFile("tpl/mount.sh")), 0o775))
+	must.Do(os.WriteFile("sample_data/reset.sh", must.Get(tpl.ReadFile("tpl/reset.sh")), 0o775))
 
 	// TODO:
 	// - create `pkg/db/errors.go`

pkg/codegen/tpl/db.go.tpl

@@ -13,7 +13,7 @@ import (
 var sql_schema string
 
 // Database starts at version 0.  First migration brings us to version 1
-var MIGRATIONS = []string{}
+var MIGRATIONS = []db.Migration{}
 
 type DB struct {
 	DB *sqlx.DB

pkg/codegen/tpl/db_test.go.tpl

@@ -3,7 +3,7 @@ package db_test
 import (
 	"fmt"
 
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 
 	. "{{ .ModuleName }}/pkg/db"
 )
@@ -14,6 +14,6 @@ func init() {
 	TestDB = MakeDB("tmp")
 }
 func MakeDB(dbName string) *DB {
-	db := Must(Create(fmt.Sprintf("file:%s?mode=memory&cache=shared", dbName)))
+	db := must.Get(Create(fmt.Sprintf("file:%s?mode=memory&cache=shared", dbName)))
 	return db
 }

pkg/db/connect.go

@@ -8,6 +8,8 @@ import (
 
 	"github.com/jmoiron/sqlx"
 	_ "github.com/mattn/go-sqlite3"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
 type DBConfig struct {
@@ -18,25 +20,11 @@ type DBConfig struct {
 	sql_schema *string
 
 	// Database starts at version 0.  First migration brings us to version 1
-	migrations     *[]string
+	migrations     *[]Migration
 	version_number uint
 }
 
-// Colors for terminal output
-const (
-	ColorReset  = "\033[0m"
-	ColorBlack  = "\033[30m"
-	ColorRed    = "\033[31m"
-	ColorGreen  = "\033[32m"
-	ColorYellow = "\033[33m"
-	ColorBlue   = "\033[34m"
-	ColorPurple = "\033[35m"
-	ColorCyan   = "\033[36m"
-	ColorGray   = "\033[37m"
-	ColorWhite  = "\033[97m"
-)
-
-func Init(schema *string, migrationsList *[]string) DBConfig {
+func Init(schema *string, migrationsList *[]Migration) DBConfig {
 	return DBConfig{
 		sql_schema:     schema,
 		migrations:     migrationsList,
@@ -96,45 +84,32 @@ func (c DBConfig) CheckAndUpdateVersion(db *sqlx.DB) error {
 	}
 
 	if c.version_number > version {
-		fmt.Print(ColorYellow)
+		fmt.Print(textutils.ColorYellow)
 		fmt.Printf("================================================\n")
 		fmt.Printf("Database version is out of date.  Upgrading database from version %d to version %d!\n", version,
 			c.version_number)
-		fmt.Print(ColorReset)
-		c.UpgradeFromXToY(db, version, c.version_number)
+		fmt.Print(textutils.ColorReset)
+
+		for i := version; i < c.version_number; i++ {
+			m := (*c.migrations)[i]
+			if err := m.Apply(db); err != nil {
+				return fmt.Errorf("migration %d: %w", m.ID, err)
+			}
+
+			fmt.Print(textutils.ColorYellow)
+			fmt.Printf("Now at database schema version %d.\n", m.ID)
+			fmt.Print(textutils.ColorReset)
+		}
+
+		fmt.Print(textutils.ColorGreen)
+		fmt.Printf("================================================\n")
+		fmt.Printf("Database version has been upgraded to version %d.\n", c.version_number)
+		fmt.Print(textutils.ColorReset)
 	}
 
 	return nil
 }
 
-// UpgradeFromXToY runs all the migrations from version X to version Y, and update the `database_version` table's `version_number`
-func (c DBConfig) UpgradeFromXToY(db *sqlx.DB, x uint, y uint) {
-	for i := x; i < y; i++ {
-		fmt.Print(ColorCyan)
-		fmt.Println((*c.migrations)[i])
-		fmt.Print(ColorReset)
-
-		// Execute the migration in a transaction
-		tx, err := db.Beginx()
-		if err != nil {
-			panic(err)
-		}
-		tx.MustExec((*c.migrations)[i])
-		tx.MustExec("update db_version set version = ?", i+1)
-		if err := tx.Commit(); err != nil {
-			panic(err)
-		}
-
-		fmt.Print(ColorYellow)
-		fmt.Printf("Now at database schema version %d.\n", i+1)
-		fmt.Print(ColorReset)
-	}
-	fmt.Print(ColorGreen)
-	fmt.Printf("================================================\n")
-	fmt.Printf("Database version has been upgraded to version %d.\n", y)
-	fmt.Print(ColorReset)
-}
-
 type VersionMismatchError struct {
 	EngineVersion   uint
 	DatabaseVersion uint

pkg/db/connect_test.go

@@ -18,7 +18,7 @@ func TestCreateAndConnectToDB(t *testing.T) {
 	_schema_sql, err := os.ReadFile("../../sample_data/test_schemas/food.sql")
 	require.NoError(t, err)
 	schema_sql := string(_schema_sql)
-	migrations := []string{}
+	migrations := []db.Migration{}
 
 	config := db.Init(&schema_sql, &migrations)
 
@@ -43,7 +43,7 @@ func TestVersionUpgrade(t *testing.T) {
 		create table db_version (version integer primary key) strict, without rowid;
 		insert into db_version values(0);
 	`
-	migrations := []string{}
+	migrations := []db.Migration{}
 	config := db.Init(&initial_schema, &migrations)
 
 	connection, err := config.Create(":memory:")
@@ -61,9 +61,9 @@ func TestVersionUpgrade(t *testing.T) {
 	require.Equal(0, get_version(connection))
 
 	// Create a migration to add a new Item
-	migrations = append(migrations, "insert into items (rowid) values (1)")
-	db.Init(&initial_schema, &migrations) // Reinitialize with the new migration
-	config.UpgradeFromXToY(connection, uint(len(migrations)-1), uint(len(migrations)))
+	migrations = append(migrations, db.Migration{ID: 1, SQL: "insert into items (rowid) values (1)"})
+	config = db.Init(&initial_schema, &migrations) // Reinitialize with the new migration
+	require.NoError(config.CheckAndUpdateVersion(connection))
 
 	var items2 []int
 	require.NoError(connection.Select(&items2, "select * from items"))
@@ -71,9 +71,9 @@ func TestVersionUpgrade(t *testing.T) {
 	require.Equal(1, get_version(connection))
 
 	// Create a migration to add a new Item
-	migrations = append(migrations, `alter table items add column name string default 'asdf'`)
+	migrations = append(migrations, db.Migration{ID: 2, SQL: `alter table items add column name string default 'asdf'`})
 	config = db.Init(&initial_schema, &migrations) // Reinitialize with the new migration
-	config.UpgradeFromXToY(connection, uint(len(migrations)-1), uint(len(migrations)))
+	require.NoError(config.CheckAndUpdateVersion(connection))
 
 	var items3 []struct {
 		ID   uint64 `db:"rowid"`

pkg/db/errors.go

@@ -12,6 +12,8 @@ var (
 	ErrItemIsDeleted         = errors.New("item is deleted")
 	ErrForeignKeyViolation   = errors.New("foreign key constraint failed")
 	ErrDatabaseAlreadyExists = errors.New("target already exists")
+
+	ErrMigrationOrder = errors.New("migration in wrong order")
 )
 
 type ForeignKey interface {

pkg/db/migration.go

@@ -0,0 +1,50 @@
+package db
+
+import (
+	"fmt"
+
+	"github.com/jmoiron/sqlx"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
+)
+
+type Migration struct {
+	// ID is the version number that the schema will be at, after applying the migration.
+	ID int
+
+	// Title is an optional name for the migration.
+	Title string
+
+	// SQL is the body of the migration that will be executed.
+	SQL string
+}
+
+// Apply runs the migration in a transaction.  Foreign key checking is delayed until right before committing the transaction.
+func (m Migration) Apply(db *sqlx.DB) error {
+	fmt.Print(textutils.ColorCyan)
+	fmt.Println(m.SQL)
+	fmt.Print(textutils.ColorReset)
+
+	// Temporarily suspend foreign keys until the migration is finished
+	db.MustExec("pragma foreign_keys = off")
+	defer db.MustExec("pragma foreign_keys = on")
+
+	tx := db.MustBegin()
+	defer func() { _ = tx.Rollback() }()
+
+	// Sanity: should initially be on the previous version
+	var prevVersion int
+	must.Do(tx.Get(&prevVersion, `select version from db_version`))
+	if prevVersion != m.ID-1 {
+		return fmt.Errorf("%w: tried to apply migration %d on DB version %d", ErrMigrationOrder, m.ID, prevVersion)
+	}
+
+	// Execute the migration
+	tx.MustExec(m.SQL)
+	tx.MustExec("update db_version set version = ?", m.ID)
+	must.Do(PragmaForeignKeyCheck(tx))
+	must.Do(tx.Commit())
+
+	return nil
+}

pkg/db/migration_test.go

@@ -0,0 +1,260 @@
+package db_test
+
+import (
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
+)
+
+// migrationTestSchema has a foreign key (`children.parent_id` => `parents.rowid`) along with one
+// valid parent/child pair, so that migrations can be written which either preserve or break
+// referential integrity.
+var migrationTestSchema = `
+	create table db_version (version integer primary key) strict, without rowid;
+	insert into db_version values (0);
+
+	create table parents (
+		rowid integer primary key,
+		name text not null
+	);
+	insert into parents (rowid, name) values (1, 'p1');
+
+	create table children (
+		rowid integer primary key,
+		parent_id integer not null references parents(rowid)
+	);
+	insert into children (rowid, parent_id) values (1, 1);
+`
+
+func newMigrationTestDB() *sqlx.DB {
+	return must.Get(db.Init(&migrationTestSchema, &[]db.Migration{}).Create(":memory:"))
+}
+
+func assertForeignKeysAreGood(t *testing.T, conn *sqlx.DB) {
+	t.Helper()
+
+	// FKs should be enabled and intact at all times
+	var fkEnabled bool
+	require.NoError(t, conn.Get(&fkEnabled, `pragma foreign_keys`))
+	assert.True(t, fkEnabled)
+	assert.NoError(t, db.PragmaForeignKeyCheck(conn))
+
+	// ...and enforcement should be in effect again, not merely reported as on
+	_, err := conn.Exec(`insert into children (rowid, parent_id) values (99, 40235235234)`)
+	assert.True(t, db.IsSqliteFkError(err), "expected a foreign key error, got: %v", err)
+}
+
+func TestMigrationApply(t *testing.T) {
+	conn := newMigrationTestDB()
+
+	testcases := []struct {
+		Migration        db.Migration
+		ExpectedParents  int
+		ExpectedChildren int
+	}{
+		{
+			Migration: db.Migration{
+				ID:    1,
+				Title: "add a second parent",
+				SQL:   `insert into parents (rowid, name) values (2, 'p2')`,
+			},
+			ExpectedParents:  2,
+			ExpectedChildren: 1,
+		},
+		{
+			Migration: db.Migration{ID: 2, SQL: `
+				insert into children (rowid, parent_id) values (2, 2);
+				insert into parents (rowid, name) values (3, 'p3');
+			`},
+			ExpectedParents:  3,
+			ExpectedChildren: 2,
+		},
+	}
+
+	for _, tc := range testcases {
+		t.Run(tc.Migration.Title, func(t *testing.T) {
+			require.NoError(t, tc.Migration.Apply(conn))
+
+			// Check that it applied
+			var parents int
+			require.NoError(t, conn.Get(&parents, `select count(*) from parents`))
+			assert.Equal(t, tc.ExpectedParents, parents)
+			var children int
+			require.NoError(t, conn.Get(&children, `select count(*) from children`))
+			assert.Equal(t, tc.ExpectedChildren, children)
+
+			// Should bump the DB version
+			var version int
+			require.NoError(t, conn.Get(&version, `select version from db_version`))
+			assert.Equal(t, tc.Migration.ID, version, "db version should be bumped to the migration's ID")
+
+			assertForeignKeysAreGood(t, conn)
+		})
+	}
+}
+
+// A migration whose SQL fails must leave no trace, including the statements which had already
+// succeeded before the failing one.  Every migration below therefore starts by creating
+// `new_table`, which must never survive.
+func TestMigrationFailureRollsBack(t *testing.T) {
+	conn := newMigrationTestDB()
+
+	nothingHappens := func(t *testing.T) {
+		t.Helper()
+		// Everything should be rolled back, including the statements which ran before the failing one
+		var newTables int
+		require.NoError(t, conn.Get(&newTables, `select count(*) from sqlite_master where type = 'table' and name = 'new_table'`))
+		assert.Equal(t, 0, newTables, "the migration's earlier statements should be rolled back too")
+
+		var version int
+		require.NoError(t, conn.Get(&version, `select version from db_version`))
+		assert.Equal(t, 0, version)
+
+		var parents int
+		require.NoError(t, conn.Get(&parents, `select count(*) from parents`))
+		assert.Equal(t, 1, parents)
+
+		var children int
+		require.NoError(t, conn.Get(&children, `select count(*) from children`))
+		assert.Equal(t, 1, children)
+	}
+
+	testcases2 := []db.Migration{
+		{
+			ID:    1,
+			Title: "syntax error",
+			SQL: `
+				create table new_table (rowid integer primary key);
+				this is not valid sql;
+			`,
+		},
+		{
+			ID:    1,
+			Title: "unknown table",
+			SQL: `
+				create table new_table (rowid integer primary key);
+				insert into no_such_table (rowid) values (1);
+			`,
+		},
+		{
+			ID:    1,
+			Title: "constraint violation",
+			SQL: `
+				create table new_table (rowid integer primary key);
+				insert into parents (rowid, name) values (1, 'duplicate rowid');
+			`,
+		},
+		{
+			ID:    1,
+			Title: "failure after a successful write",
+			SQL: `
+				create table new_table (rowid integer primary key);
+				insert into parents (rowid, name) values (2, 'p2');
+				insert into parents (rowid, name) values (1, 'duplicate rowid');
+			`,
+		},
+	}
+	for _, tc := range testcases2 {
+		t.Run(tc.Title, func(t *testing.T) {
+			assert.Panics(t, func() { _ = tc.Apply(conn) })
+			nothingHappens(t)
+			assertForeignKeysAreGood(t, conn)
+		})
+	}
+
+	// ---------
+	// Foreign key failures should trigger a rollback too
+	// ---------
+
+	testcases := []db.Migration{
+		{
+			ID:    1,
+			Title: "child pointing at a nonexistent parent",
+			SQL: `
+				create table new_table (rowid integer primary key);
+				insert into children (rowid, parent_id) values (2, 404);
+			`,
+		},
+		{
+			ID:    1,
+			Title: "parent deleted out from under an existing child",
+			SQL: `
+				create table new_table (rowid integer primary key);
+				delete from parents where rowid = 1;
+			`,
+		},
+	}
+	for _, tc := range testcases {
+		t.Run(tc.Title, func(t *testing.T) {
+			// Should notify with the correct detail about the error
+			func() {
+				defer func() {
+					err := recover()
+					require.NotNil(t, err)
+					switch err := err.(type) {
+					case error:
+						var violations db.PragmaFKViolations
+						require.ErrorAs(t, err, &violations)
+						require.Len(t, violations, 1)
+						assert.Equal(t, "children", violations[0].SrcTable)
+						assert.Equal(t, "parents", violations[0].DstTable)
+					default:
+						panic(err) // Something weird happened
+					}
+				}()
+				_ = tc.Apply(conn)
+			}()
+
+			// ...as well as the usual
+			nothingHappens(t)
+			assertForeignKeysAreGood(t, conn)
+		})
+	}
+}
+
+// Migrations are sequential: a migration may only be applied to a DB sitting at the immediately
+// preceding version.
+func TestMigrationApplyRejectsOutOfOrderMigrations(t *testing.T) {
+	const sql = `insert into parents (name) values ('p2')`
+
+	t.Run("migration from the future", func(t *testing.T) {
+		conn := newMigrationTestDB()
+
+		err := db.Migration{ID: 2, SQL: sql}.Apply(conn)
+		require.ErrorIs(t, err, db.ErrMigrationOrder)
+
+		var version int
+		require.NoError(t, conn.Get(&version, `select version from db_version`))
+		assert.Equal(t, 0, version)
+
+		var parents int
+		require.NoError(t, conn.Get(&parents, `select count(*) from parents`))
+		assert.Equal(t, 1, parents, "the migration's SQL should not have run")
+
+		assertForeignKeysAreGood(t, conn)
+	})
+
+	t.Run("migration applied twice", func(t *testing.T) {
+		conn := newMigrationTestDB()
+		m := db.Migration{ID: 1, SQL: sql}
+		require.NoError(t, m.Apply(conn))
+
+		err := m.Apply(conn)
+		require.ErrorIs(t, err, db.ErrMigrationOrder)
+
+		var version int
+		require.NoError(t, conn.Get(&version, `select version from db_version`))
+		assert.Equal(t, 1, version)
+
+		var parents int
+		require.NoError(t, conn.Get(&parents, `select count(*) from parents`))
+		assert.Equal(t, 2, parents, "the migration's SQL should not have run again")
+
+		assertForeignKeysAreGood(t, conn)
+	})
+}

pkg/db/pragma_fk_check.go

@@ -0,0 +1,42 @@
+package db
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/jmoiron/sqlx"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
+)
+
+// PragmaFKViolation is a result row of SQLite's `pragma foreign_key_check`.
+type PragmaFKViolation struct {
+	SrcTable      string `db:"table"`
+	SrcRowid      int    `db:"rowid"`
+	DstTable      string `db:"parent"`
+	ForeignKeyIdx int    `db:"fkid"`
+}
+
+// PragmaFKViolations is a slice of FK violations.  It also implements the `error` interface.
+type PragmaFKViolations []PragmaFKViolation
+
+func (v PragmaFKViolations) Error() string {
+	var b strings.Builder
+	for i, fkv := range v {
+		if i > 0 {
+			b.WriteString("\n")
+		}
+		fmt.Fprintf(&b, "Item #%d in table %q has invalid reference to table %q", fkv.SrcRowid, fkv.SrcTable, fkv.DstTable)
+	}
+	return b.String()
+}
+
+// PragmaForeignKeyCheck uses `pragma foreign_key_check` to do a full database check for any FK violations.
+func PragmaForeignKeyCheck(q sqlx.Queryer) error {
+	var ret PragmaFKViolations
+	must.Do(sqlx.Select(q, &ret, `pragma foreign_key_check`))
+	if len(ret) == 0 {
+		return nil
+	}
+	return ret
+}

pkg/db/vsc.go

@@ -0,0 +1,51 @@
+package db
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"errors"
+	"strings"
+)
+
+const separator = "\x1f"
+
+type VSC []string
+
+// MarshalJSON replaces `nil` with `[]` for hygiene.
+func (vs VSC) MarshalJSON() ([]byte, error) {
+	if vs == nil {
+		vs = VSC{}
+	}
+	return json.Marshal([]string(vs)) //nolint: wrapcheck // Passthrough
+}
+
+func (vs VSC) Value() (driver.Value, error) {
+	fields := make([]string, len(vs))
+	for i, v := range vs {
+		fields[i] = strings.ReplaceAll(v, separator, "")
+	}
+	return strings.Join(fields, separator), nil
+}
+
+var ErrWrongVSCType = errors.New("incompatible DB type for VSC")
+
+func (vs *VSC) Scan(src any) error {
+	var s string
+	switch v := src.(type) {
+	case string:
+		s = v
+	case []byte:
+		s = string(v)
+	case nil:
+		*vs = nil
+		return nil
+	default:
+		return ErrWrongVSCType
+	}
+	if s == "" {
+		*vs = VSC{}
+		return nil
+	}
+	*vs = strings.Split(s, separator)
+	return nil
+}

pkg/db/vsc_test.go

@@ -0,0 +1,48 @@
+package db_test
+
+import (
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/stretchr/testify/require"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"
+)
+
+func TestVSCDBRoundTrip(t *testing.T) {
+	conn, err := sqlx.Open("sqlite3", ":memory:")
+	require.NoError(t, err)
+	t.Cleanup(func() { require.NoError(t, conn.Close()) })
+
+	_, err = conn.Exec(`create table vsc_items (id integer primary key, items text not null)`)
+	require.NoError(t, err)
+
+	type vscRow struct {
+		ID    int    `db:"id"`
+		Items db.VSC `db:"items"`
+	}
+
+	for _, want := range []vscRow{
+		{ID: 1, Items: db.VSC{"email"}},
+		{ID: 2, Items: db.VSC{"email", "profile"}},
+		{ID: 3, Items: db.VSC{}},
+	} {
+		_, err = conn.NamedExec(`insert into vsc_items (id, items) values (:id, :items)`, want)
+		require.NoError(t, err)
+
+		var got vscRow
+		require.NoError(t, conn.Get(&got, `select id, items from vsc_items where id = ?`, want.ID))
+		require.Equal(t, want, got)
+	}
+	t.Run("nil gets upgrade to empty list", func(t *testing.T) {
+		want := vscRow{ID: 4, Items: nil}
+		_, err = conn.NamedExec(`insert into vsc_items (id, items) values (:id, :items)`, want)
+		require.NoError(t, err)
+
+		var got vscRow
+		require.NoError(t, conn.Get(&got, `select id, items from vsc_items where id = ?`, want.ID))
+		require.NotNil(t, got.Items)
+		require.Equal(t, db.VSC{}, got.Items)
+	})
+}

pkg/flowutils/flowutils.go

@@ -1,18 +0,0 @@
-package flowutils
-
-import "io"
-
-func PanicIf(err error) {
-	if err != nil {
-		panic(err)
-	}
-}
-
-func Must[T any](val T, err error) T {
-	PanicIf(err)
-	return val
-}
-
-func MustClose(closer io.Closer) {
-	PanicIf(closer.Close())
-}

pkg/generic/mutexmap.go

@@ -0,0 +1,76 @@
+package generic
+
+import (
+	"maps"
+	"sync"
+)
+
+type MutexMap[K comparable, V any] struct {
+	mu       sync.RWMutex
+	contents map[K]V
+}
+
+func NewMutexMap[K comparable, V any]() *MutexMap[K, V] {
+	return &MutexMap[K, V]{contents: make(map[K]V)}
+}
+
+func (m *MutexMap[K, V]) Set(key K, value V) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.contents[key] = value
+}
+
+func (m *MutexMap[K, V]) Get(key K) (V, bool) {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	v, ok := m.contents[key]
+	return v, ok
+}
+
+func (m *MutexMap[K, V]) Len() int {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	return len(m.contents)
+}
+
+// Upd atomically updates the value for key.  `fn` is used to determine how to update an existing
+// value, if there is one.  It will be passed the existing value, and should return `(newValue V, shouldReplace bool)`.
+//
+// Returns the value that ends up associated with key after the call and whether an update occurred.
+func (m *MutexMap[K, V]) Upd(key K, fn func(prev V) (next V, shouldReplace bool)) (V, bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	prev := m.contents[key]
+	if next, shouldReplace := fn(prev); shouldReplace {
+		m.contents[key] = next
+		return next, true
+	}
+	return prev, false
+}
+
+// Del removes key from the map. Returns true if the key was present.
+func (m *MutexMap[K, V]) Del(key K) bool { //nolint: boolnames // Return value is incidental, not the main purpose of the function
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if _, ok := m.contents[key]; !ok {
+		return false
+	}
+	delete(m.contents, key)
+	return true
+}
+
+func (m *MutexMap[K, V]) Cpy() map[K]V {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	cp := make(map[K]V, len(m.contents))
+	maps.Copy(cp, m.contents)
+	return cp
+}
+
+func (m *MutexMap[K, V]) Pop(key K) (ret V, isOk bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	ret, isOk = m.contents[key]
+	delete(m.contents, key)
+	return
+}

pkg/must/must.go

@@ -0,0 +1,27 @@
+package must
+
+import (
+	"fmt"
+	"io"
+)
+
+func Do(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+func Get[T any](val T, err error) T {
+	Do(err)
+	return val
+}
+
+func Be(condition bool, msg string, args ...any) {
+	if !condition {
+		panic(fmt.Errorf(msg, args...)) //nolint:err113 // not a returned error
+	}
+}
+
+func Close(closer io.Closer) {
+	Do(closer.Close())
+}

pkg/schema/column.go

@@ -0,0 +1,61 @@
+package schema
+
+import (
+	"strings"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
+)
+
+// Column represents a single column in a table.
+type Column struct {
+	TableName              string `db:"table_name"`
+	Name                   string `db:"column_name"`
+	Type                   string `db:"column_type"`
+	IsNotNull              bool   `db:"notnull"`
+	HasDefaultValue        bool   `db:"has_default_value"`
+	DefaultValue           string `db:"dflt_value"`
+	IsPrimaryKey           bool   `db:"is_primary_key"`
+	PrimaryKeyRank         uint   `db:"primary_key_rank"`
+	IsForeignKey           bool   `db:"is_foreign_key"`
+	ForeignKeyTargetTable  string `db:"fk_target_table"`
+	ForeignKeyTargetColumn string `db:"fk_target_column"`
+}
+
+// IsNullableForeignKey is a helper function.
+func (c Column) IsNullableForeignKey() bool {
+	return !c.IsNotNull && !c.IsPrimaryKey && c.IsForeignKey
+}
+
+func (c Column) IsNonCodeTableForeignKey() bool {
+	return c.IsForeignKey && strings.HasSuffix(c.Name, "_id")
+}
+
+func (c Column) GoFieldName() string {
+	if c.Name == "rowid" {
+		return "ID"
+	}
+	if c.IsNonCodeTableForeignKey() {
+		return textutils.SnakeToCamel(strings.TrimSuffix(c.Name, "_id")) + "ID"
+	}
+	return textutils.SnakeToCamel(c.Name)
+}
+
+// GoVarName returns the name of a local variable for this column, e.g., when used as a function parameter.
+func (c Column) GoVarName() string {
+	if c.Name == "rowid" {
+		return strings.ToLower(c.TableName)[0:1] + "ID"
+		// TODO: Or should it just be "id"??
+	}
+	// For foreign keys, use first letter of the target type and "ID".  "UserID" => "uID"
+	if c.IsNonCodeTableForeignKey() {
+		return strings.ToLower(c.ForeignKeyTargetTable)[0:1] + "ID"
+	}
+
+	// Otherwise, just use the whole name
+	return c.LongGoVarName()
+}
+
+// LongGoVarName returns a lowercased version of the field name (Pascal => Camel).
+func (c Column) LongGoVarName() string {
+	return textutils.CamelToPascal(c.GoFieldName())
+}

pkg/schema/index.go

@@ -0,0 +1,19 @@
+package schema
+
+type IndexOrigin string
+
+const (
+	IndexOriginCreateIndex      = IndexOrigin("c")
+	IndexOriginUniqueConstraint = IndexOrigin("u")
+	IndexOriginPrimaryKey       = IndexOrigin("pk")
+)
+
+type Index struct {
+	Name      string `db:"index_name"`
+	TableName string `db:"table_name"`
+	Columns   []string
+	IsUnique  bool        `db:"is_unique"`
+	Origin    IndexOrigin `db:"origin"`
+	// TODO: `where ...` for partial indexes
+	// TODO: identify columns that are expressions
+}

pkg/schema/migration_verification_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"
-	"git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
 )
 
@@ -50,14 +50,14 @@ func TestVerifyCorrectMigration(t *testing.T) {
 	db1Schema := schema.SchemaFromDB(db1)
 
 	t.Run("migrate in 1 step", func(t *testing.T) {
-		migration := `
+		migration := db.Migration{ID: 1, SQL: `
 			create table t2 (
 				rowid integer primary key
 			);
 			alter table t1 add column data3 integer;
-		`
-		db2Config := db.Init(&baseSchema, &[]string{migration})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		`}
+		db2Config := db.Init(&baseSchema, &[]db.Migration{migration})
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -67,17 +67,17 @@ func TestVerifyCorrectMigration(t *testing.T) {
 	})
 
 	t.Run("migrate in 2 steps", func(t *testing.T) {
-		migration1 := `
+		migration1 := db.Migration{ID: 1, SQL: `
 			create table t2 (
 				rowid integer primary key
 			);
-		`
-		migration2 := `
+		`}
+		migration2 := db.Migration{ID: 2, SQL: `
 			alter table t1 add column data3 integer;
-		`
+		`}
 
-		db2Config := db.Init(&baseSchema, &[]string{migration1, migration2})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2Config := db.Init(&baseSchema, &[]db.Migration{migration1, migration2})
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -92,8 +92,8 @@ func TestIncorrectMigrations(t *testing.T) {
 	db1Schema := schema.SchemaFromDB(db1)
 
 	t.Run("missing migration", func(t *testing.T) {
-		db2Config := db.Init(&baseSchema, &[]string{})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2Config := db.Init(&baseSchema, &[]db.Migration{})
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -109,12 +109,14 @@ func TestIncorrectMigrations(t *testing.T) {
 	})
 
 	t.Run("incomplete migration", func(t *testing.T) {
-		db2Config := db.Init(&baseSchema, &[]string{`
+		db2Config := db.Init(&baseSchema, &[]db.Migration{
+			{ID: 1, SQL: `
 				create table t2 (
 					rowid integer primary key
 				);
-			`})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+			`},
+		})
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -130,13 +132,15 @@ func TestIncorrectMigrations(t *testing.T) {
 	})
 
 	t.Run("incorrect migration (wrong data type)", func(t *testing.T) {
-		db2Config := db.Init(&baseSchema, &[]string{`
-			create table t2 (
-				rowid integer primary key
-			);
-			alter table t1 add column data3 text;
-		`})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2Config := db.Init(&baseSchema, &[]db.Migration{
+			{ID: 1, SQL: `
+				create table t2 (
+					rowid integer primary key
+				);
+				alter table t1 add column data3 text;
+			`},
+		})
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 

pkg/schema/parse.go

@@ -10,7 +10,7 @@ import (
 	"github.com/jmoiron/sqlx"
 	_ "github.com/mattn/go-sqlite3"
 
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
@@ -38,20 +38,20 @@ func SchemaFromDB(db *sqlx.DB) Schema {
 	db.MustExec(create_views)
 
 	var tables []Table
-	PanicIf(db.Select(&tables, `select name, table_type, is_strict, is_without_rowid from tables`))
+	must.Do(db.Select(&tables, `select name, table_type, is_strict, is_without_rowid from tables`))
 	for _, tbl := range tables {
 		tbl.GoTypeName = TypenameFromTablename(tbl.TableName)
 		tbl.TypeIDName = tbl.GoTypeName + "ID"
 		tbl.VarName = strings.ToLower(string(tbl.TableName[0]))
 
-		PanicIf(db.Select(&tbl.Columns, `select * from columns where table_name = ?`, tbl.TableName))
+		must.Do(db.Select(&tbl.Columns, `select * from columns where table_name = ?`, tbl.TableName))
 		ret.Tables[tbl.TableName] = tbl
 	}
 
 	var indexes []Index
-	PanicIf(db.Select(&indexes, `select index_name, table_name, is_unique from indexes`))
+	must.Do(db.Select(&indexes, `select index_name, table_name, is_unique, origin from indexes`))
 	for _, idx := range indexes {
-		PanicIf(db.Select(&idx.Columns, `select column_name from index_columns where index_name = ? order by rank`, idx.Name))
+		must.Do(db.Select(&idx.Columns, `select column_name from index_columns where index_name = ? order by rank`, idx.Name))
 		ret.Indexes[idx.Name] = idx
 	}
 	return ret

pkg/schema/schema.go

@@ -0,0 +1,6 @@
+package schema
+
+type Schema struct {
+	Tables  map[string]Table
+	Indexes map[string]Index
+}

pkg/schema/table.go

@@ -2,65 +2,8 @@ package schema
 
 import (
 	"sort"
-	"strings"
-
-	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
-// Column represents a single column in a table.
-type Column struct {
-	TableName              string `db:"table_name"`
-	Name                   string `db:"column_name"`
-	Type                   string `db:"column_type"`
-	IsNotNull              bool   `db:"notnull"`
-	HasDefaultValue        bool   `db:"has_default_value"`
-	DefaultValue           string `db:"dflt_value"`
-	IsPrimaryKey           bool   `db:"is_primary_key"`
-	PrimaryKeyRank         uint   `db:"primary_key_rank"`
-	IsForeignKey           bool   `db:"is_foreign_key"`
-	ForeignKeyTargetTable  string `db:"fk_target_table"`
-	ForeignKeyTargetColumn string `db:"fk_target_column"`
-}
-
-// IsNullableForeignKey is a helper function.
-func (c Column) IsNullableForeignKey() bool {
-	return !c.IsNotNull && !c.IsPrimaryKey && c.IsForeignKey
-}
-
-func (c Column) IsNonCodeTableForeignKey() bool {
-	return c.IsForeignKey && strings.HasSuffix(c.Name, "_id")
-}
-
-func (c Column) GoFieldName() string {
-	if c.Name == "rowid" {
-		return "ID"
-	}
-	if c.IsNonCodeTableForeignKey() {
-		return textutils.SnakeToCamel(strings.TrimSuffix(c.Name, "_id")) + "ID"
-	}
-	return textutils.SnakeToCamel(c.Name)
-}
-
-// GoVarName returns the name of a local variable for this column, e.g., when used as a function parameter.
-func (c Column) GoVarName() string {
-	if c.Name == "rowid" {
-		return strings.ToLower(c.TableName)[0:1] + "ID"
-		// TODO: Or should it just be "id"??
-	}
-	// For foreign keys, use first letter of the target type and "ID".  "UserID" => "uID"
-	if c.IsNonCodeTableForeignKey() {
-		return strings.ToLower(c.ForeignKeyTargetTable)[0:1] + "ID"
-	}
-
-	// Otherwise, just use the whole name
-	return c.LongGoVarName()
-}
-
-// LongGoVarName returns a lowercased version of the field name (Pascal => Camel).
-func (c Column) LongGoVarName() string {
-	return textutils.CamelToPascal(c.GoFieldName())
-}
-
 // Table is a single SQLite table.
 type Table struct {
 	TableName string `db:"name"`
@@ -119,16 +62,35 @@ func (t Table) HasAutoTimestamps() (hasCreatedAt bool, hasUpdatedAt bool) {
 	return
 }
 
-type Index struct {
-	Name      string `db:"index_name"`
-	TableName string `db:"table_name"`
-	Columns   []string
-	IsUnique  bool `db:"is_unique"`
-	// TODO: `where ...` for partial indexes
-	// TODO: identify columns that are expressions
+// HasSoftDelete reports whether this table supports soft-deletion, i.e., whether it has both
+// an "is_deleted" and a "deleted_at" column.
+func (t Table) HasSoftDelete() bool {
+	var hasIsDeleted, hasDeletedAt bool
+	for _, c := range t.Columns {
+		if c.Name == "is_deleted" && c.Type == "integer" {
+			hasIsDeleted = true
+		}
+		if c.Name == "deleted_at" && c.Type == "integer" {
+			hasDeletedAt = true
+		}
+	}
+	return hasIsDeleted && hasDeletedAt
 }
 
-type Schema struct {
-	Tables  map[string]Table
-	Indexes map[string]Index
+// GetUpdateableColumns returns the columns that should be written to by an "update" operation.
+func (t Table) GetUpdateableColumns() (ret []Column) {
+	hasCreatedAt, _ := t.HasAutoTimestamps()
+	for _, col := range t.Columns {
+		if col.Name == "rowid" || col.IsPrimaryKey {
+			continue // Rowid / primary key is never updateable
+		}
+		if col.Name == "created_at" && hasCreatedAt {
+			continue // Update shouldn't write `created_at`
+		}
+		if t.HasSoftDelete() && (col.Name == "is_deleted" || col.Name == "deleted_at") {
+			continue // Soft-delete state is managed by SoftDeleteXyz(), not by updates
+		}
+		ret = append(ret, col)
+	}
+	return
 }

pkg/schema/table_test.go

@@ -0,0 +1,34 @@
+package schema
+
+import "testing"
+
+func TestTableGetUpdateableColumns(t *testing.T) {
+	tbl := Table{
+		Columns: []Column{
+			{Name: "rowid"},
+			{Name: "version", Type: "integer", IsPrimaryKey: true},
+			{Name: "created_at", Type: "integer"},
+			{Name: "updated_at", Type: "integer"},
+			{Name: "is_deleted", Type: "integer"},
+			{Name: "deleted_at", Type: "integer"},
+			{Name: "owner_id", Type: "integer", IsForeignKey: true},
+			{Name: "name", Type: "text"},
+		},
+	}
+
+	gotColumns := tbl.GetUpdateableColumns()
+	got := make([]string, 0, len(gotColumns))
+	for _, col := range gotColumns {
+		got = append(got, col.Name)
+	}
+
+	want := []string{"updated_at", "owner_id", "name"}
+	if len(got) != len(want) {
+		t.Fatalf("GetUpdateableColumns() = %v, want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("GetUpdateableColumns() = %v, want %v", got, want)
+		}
+	}
+}

pkg/schema/views.sql

@@ -27,7 +27,8 @@ create temporary view columns as
 create temporary view indexes as
     select idx.name as index_name,
            tables.name as table_name,
-           idx."unique" as is_unique
+           idx."unique" as is_unique,
+           idx.origin as origin
       from tables
       join pragma_index_list(tables.name) idx;
 

pkg/textutils/terminal_colors.go

@@ -0,0 +1,15 @@
+package textutils
+
+// Colors for terminal output
+const (
+	ColorReset  = "\033[0m"
+	ColorBlack  = "\033[30m"
+	ColorRed    = "\033[31m"
+	ColorGreen  = "\033[32m"
+	ColorYellow = "\033[33m"
+	ColorBlue   = "\033[34m"
+	ColorPurple = "\033[35m"
+	ColorCyan   = "\033[36m"
+	ColorGray   = "\033[37m"
+	ColorWhite  = "\033[97m"
+)

pkg/version/version.go

@@ -0,0 +1,55 @@
+package version
+
+import (
+	"fmt"
+	"runtime/debug"
+)
+
+// Version is stamped in at compile time by `ops/compile.sh`, via:
+//
+//	-ldflags "-X git.offline-twitter.com/offline-labs/gas-stack/pkg/version.Version=v0.0.4"
+//
+// It's empty for builds that don't go through that script-- most importantly
+// `go install git.offline-twitter.com/offline-labs/gas-stack/cmd@v0.0.4`, which is the normal way
+// to install `gas`.  In that case, String() recovers the version from the build info that the Go
+// toolchain embeds in every binary.
+var Version = ""
+
+// String returns the version of this binary, e.g. "v0.0.4".
+func String() string {
+	if Version != "" {
+		return Version
+	}
+
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "unknown"
+	}
+
+	// Set by `go install module@version`, and (as of Go 1.24) by `go build` in a git checkout
+	// that has the tags available.  It's "(devel)" if the toolchain couldn't work out a version.
+	if info.Main.Version != "" && info.Main.Version != "(devel)" {
+		return info.Main.Version
+	}
+
+	// No module version, so fall back to the commit.  This happens when building from a source
+	// tree with no usable VCS metadata: a git worktree, a `.git`-less export, or `-buildvcs=false`.
+	var revision, dirty string
+	for _, setting := range info.Settings {
+		switch setting.Key {
+		case "vcs.revision":
+			revision = setting.Value
+		case "vcs.modified":
+			if setting.Value == "true" {
+				dirty = "-dirty"
+			}
+		}
+	}
+	if revision == "" {
+		return "unknown"
+	}
+	if len(revision) > 12 {
+		revision = revision[:12]
+	}
+	return fmt.Sprintf("devel-%s%s", revision, dirty)
+}