codegen: implement auto-timestamps for created_at and updated_at

ops/gas_init_test.sh

@@ -40,7 +40,9 @@ 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 '',
-    flavor integer references item_flavor(rowid)
+    flavor integer references item_flavor(rowid),
+    created_at integer not null,
+    updated_at integer not null
 ) strict;
 EOF
 

pkg/codegen/modelgenerate/generate_model.go

@@ -97,6 +97,9 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 	insertVals := make([]string, 0, len(tbl.Columns))
 	updatePairs := make([]string, 0, len(tbl.Columns))
 
+	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
+
+	// Assemble data for building SQL "insert" and "update" strings
 	for _, col := range tbl.Columns {
 		if col.Name == "rowid" {
 			continue
@@ -107,8 +110,14 @@ 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
+		}
 		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, ", "))
+	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           "))
 
 	hasFks := false
 	checkForeignKeyFailuresAssignment := &ast.AssignStmt{
@@ -235,15 +244,20 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 		},
 	}
 
-	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, ", "))
-	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           "))
-
 	funcBody := &ast.BlockStmt{
 		List: func() []ast.Stmt {
 			ret := []ast.Stmt{}
 			if hasFks {
 				ret = append(ret, checkForeignKeyFailuresAssignment)
 			}
+			if hasUpdatedAt {
+				// Auto-timestamps: updated_at
+				ret = append(ret, &ast.AssignStmt{
+					Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("UpdatedAt")}},
+					Tok: token.ASSIGN,
+					Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+				})
+			}
 			// if item.ID == 0 {...} else {...}
 			ret = append(ret, &ast.IfStmt{
 				Cond: &ast.BinaryExpr{
@@ -255,6 +269,15 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 					// Do create
 					List: append(
 						func() []ast.Stmt {
+							ret := []ast.Stmt{}
+							if hasCreatedAt {
+								// Auto-timestamps: created_at
+								ret = append(ret, &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{}}},
+								})
+							}
 							namedExecStmt := &ast.CallExpr{
 								Fun: &ast.SelectorExpr{X: ast.NewIdent("db.DB"), Sel: ast.NewIdent("NamedExec")},
 								Args: []ast.Expr{
@@ -264,19 +287,17 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 							}
 							if !hasFks {
 								// No foreign key checking needed; just use `Must` for brevity
-								return []ast.Stmt{
+								return append(ret, &ast.AssignStmt{
-									&ast.AssignStmt{
 									Lhs: []ast.Expr{ast.NewIdent("result")},
 									Tok: token.DEFINE,
 									Rhs: []ast.Expr{&ast.CallExpr{
 										Fun:  ast.NewIdent("Must"),
 										Args: []ast.Expr{namedExecStmt},
 									}},
-									},
+								})
-								}
 							}
 
-							return []ast.Stmt{
+							return append(ret,
 								// result, err := db.DB.NamedExec(`...`, u)
 								&ast.AssignStmt{
 									Lhs: []ast.Expr{
@@ -329,7 +350,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 										},
 									},
 								},
-							}
+							)
 						}(),
 						&ast.AssignStmt{
 							Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("ID")}},

pkg/schema/table.go

@@ -46,6 +46,18 @@ type Table struct {
 	GoTypeName string
 }
 
+func (t Table) HasAutoTimestamps() (hasCreatedAt bool, hasUpdatedAt bool) {
+	for _, c := range t.Columns {
+		if c.Name == "created_at" && c.Type == "integer" {
+			hasCreatedAt = true
+		}
+		if c.Name == "updated_at" && c.Type == "integer" {
+			hasUpdatedAt = true
+		}
+	}
+	return
+}
+
 type Index struct {
 	Name      string `db:"index_name"`
 	TableName string `db:"table_name"`