codegen: generate getters for non-unique indexes

pkg/codegen/modelgenerate/generate_model.go

@@ -680,6 +680,49 @@ func GenerateGetItemByUniqColFunc(tbl schema.Table, col schema.Column) *ast.Func
 	}
 }
 
+// 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 {
+	// Use the xyzSQLFields constant in the select query
+	selectExpr := &ast.BinaryExpr{
+		X: &ast.BinaryExpr{
+			X:  &ast.BasicLit{Kind: token.STRING, Value: "`\n\t    select `"},
+			Op: token.ADD,
+			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)},
+	}
+
+	param := ast.NewIdent(col.GoVarName())
+
+	selectCall := doCall(&ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Select")},
+		Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")}, selectExpr, param},
+	})
+
+	return &ast.FuncDecl{
+		Recv: dbRecv,
+		Name: ast.NewIdent("Get" + inflection.Plural(schema.TypenameFromTablename(tbl.TableName)) + "By" + col.GoFieldName()),
+		Type: &ast.FuncType{
+			Params: &ast.FieldList{List: []*ast.Field{
+				{Names: []*ast.Ident{param}, Type: GoTypeForColumn(col)},
+			}},
+			Results: &ast.FieldList{List: []*ast.Field{
+				{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: &ast.ArrayType{Elt: ast.NewIdent(tbl.GoTypeName)}},
+			}},
+		},
+		Body: &ast.BlockStmt{
+			List: []ast.Stmt{
+				&ast.ExprStmt{X: selectCall},
+				&ast.ReturnStmt{},
+			},
+		},
+	}
+}
+
 // 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 {