codegen: handle nullable foreign keys using 'ifnull' and add a test case for them

doc/TODO.txt

@@ -15,3 +15,17 @@ TODO: generator-foreign-keys
 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)
+    - or just rowid instead of hash?  Migration sequence should be immutable after publishing, so there should never be "conflicts"
+
+TODO: language-server-for-TODO.txt
+
+TODO: auto-migration-checker
+- Use `pkg/schema` to test whether a base schema plus a migration equals a new schema
+
+TODO: codegen `without rowid` tables properly
+
+TODO: generated test file inclues global test DB setup, which is wrong

ops/devcontainer/Dockerfile

@@ -10,6 +10,8 @@ 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 GOBIN=/usr/local/bin go install git.offline-twitter.com/offline-labs/gocheckout@v0.0.2
 
+COPY etc/group /etc/group
+
 # Create a user in the container with the same UID as on the host machine, to avoid ownership conflicts.
 # The user gets sudo of course.
 #

ops/devcontainer/etc/group

@@ -0,0 +1,3 @@
+root:x:0:
+nogroup:x:65533:
+nobody:x:65534:

ops/gas_init_test.sh

@@ -31,9 +31,12 @@ cd $test_project
 
 # Create a new table in the schema
 cat >> pkg/db/schema.sql <<EOF
+create table item_flavor (rowid integer primary key, name text not null) strict;
+
 create table items (
     rowid integer primary key,
-    description text not null default ''
+    description text not null default '',
+    flavor integer references item_flavor(rowid)
 ) strict;
 EOF
 

pkg/codegen/modelgenerate/generate_model.go

@@ -52,7 +52,7 @@ func GenerateModelAST(table schema.Table) *ast.GenDecl {
 					} else if strings.HasSuffix(col.Name, "_at") {
 						typeName = "Timestamp"
 					} else {
-						typeName = "int64"
+						typeName = "int"
 					}
 				case "text":
 					typeName = "string"
@@ -258,12 +258,12 @@ func GenerateGetAllItemsFunc(tbl schema.Table) *ast.FuncDecl {
 					&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")},
 					&ast.BinaryExpr{
 						X: &ast.BinaryExpr{
-							X:  &ast.BasicLit{Kind: token.STRING, Value: "`SELECT `"},
+							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 + "`"},
+						Y:  &ast.BasicLit{Kind: token.STRING, Value: "` from " + tbl.TableName + "`"},
 					},
 				},
 			},
@@ -351,8 +351,12 @@ func GenerateDeleteItemFunc(tbl schema.Table) *ast.FuncDecl {
 func GenerateSQLFieldsConst(tbl schema.Table) *ast.GenDecl {
 	columns := make([]string, 0, len(tbl.Columns))
 	for _, col := range tbl.Columns {
+		if col.IsNullableForeignKey() {
+			columns = append(columns, fmt.Sprintf("ifnull(%s, 0) %s", col.Name, col.Name))
+		} else {
 			columns = append(columns, col.Name)
 		}
+	}
 	// Join with comma and space
 	value := "`" + strings.Join(columns, ", ") + "`"