Add EmitResultSlicePointer option for result slice pointer emission

Author: Alexfilus

internal/gen.go

@@ -10,10 +10,10 @@ import (
 	"strings"
 	"text/template"
 
-	"github.com/sqlc-dev/sqlc-gen-go/internal/opts"
-	"github.com/sqlc-dev/plugin-sdk-go/sdk"
 	"github.com/sqlc-dev/plugin-sdk-go/metadata"
 	"github.com/sqlc-dev/plugin-sdk-go/plugin"
+	"github.com/sqlc-dev/plugin-sdk-go/sdk"
+	"github.com/sqlc-dev/sqlc-gen-go/internal/opts"
 )
 
 type tmplCtx struct {
@@ -34,6 +34,7 @@ type tmplCtx struct {
 	EmitPreparedQueries       bool
 	EmitInterface             bool
 	EmitEmptySlices           bool
+	EmitResultSlicePointer    bool
 	EmitMethodsWithDBArgument bool
 	EmitEnumValidMethod       bool
 	EmitAllEnumValues         bool
@@ -178,6 +179,7 @@ func generate(req *plugin.GenerateRequest, options *opts.Options, enums []Enum,
 		EmitDBTags:                options.EmitDbTags,
 		EmitPreparedQueries:       options.EmitPreparedQueries,
 		EmitEmptySlices:           options.EmitEmptySlices,
+		EmitResultSlicePointer:    options.EmitResultSlicePointer,
 		EmitMethodsWithDBArgument: options.EmitMethodsWithDbArgument,
 		EmitEnumValidMethod:       options.EmitEnumValidMethod,
 		EmitAllEnumValues:         options.EmitAllEnumValues,

internal/opts/options.go

@@ -19,6 +19,7 @@ type Options struct {
 	EmitEmptySlices           bool `json:"emit_empty_slices,omitempty" yaml:"emit_empty_slices"`
 	EmitExportedQueries       bool `json:"emit_exported_queries" yaml:"emit_exported_queries"`
 	EmitResultStructPointers  bool `json:"emit_result_struct_pointers" yaml:"emit_result_struct_pointers"`
+	EmitResultSlicePointer    bool `json:"emit_result_slice_pointer" yaml:"emit_result_slice_pointer"`
 	EmitParamsStructPointers  bool `json:"emit_params_struct_pointers" yaml:"emit_params_struct_pointers"`
 	EmitMethodsWithDbArgument bool `json:"emit_methods_with_db_argument,omitempty" yaml:"emit_methods_with_db_argument"`
 	EmitPointersForNullTypes  bool `json:"emit_pointers_for_null_types" yaml:"emit_pointers_for_null_types"`

internal/templates/pgx/queryCode.tmpl

@@ -49,6 +49,31 @@ func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ({{.Ret.De
 {{if eq .Cmd ":many"}}
 {{range .Comments}}//{{.}}
 {{end -}}
+{{- if $.EmitResultSlicePointer -}}
+{{- if $.EmitMethodsWithDBArgument -}}
+func (q *Queries) {{.MethodName}}(ctx context.Context, db DBTX, {{if .Arg.Pair}}{{.Arg.Pair}}, {{end}}dest *[]{{.Ret.DefineType}}) error {
+	rows, err := db.Query(ctx, {{.ConstantName}}{{if .Arg.Params}}, {{.Arg.Params}}{{end}})
+{{- else -}}
+func (q *Queries) {{.MethodName}}(ctx context.Context, {{if .Arg.Pair}}{{.Arg.Pair}}, {{end}}dest *[]{{.Ret.DefineType}}) error {
+	rows, err := q.db.Query(ctx, {{.ConstantName}}{{if .Arg.Params}}, {{.Arg.Params}}{{end}})
+{{- end}}
+	if err != nil {
+		return {{if $.WrapErrors}}fmt.Errorf("query {{.MethodName}}: %w", err){{else}}err{{end}}
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var {{.Ret.Name}} {{.Ret.Type}}
+		if err := rows.Scan({{.Ret.Scan}}); err != nil {
+			return {{if $.WrapErrors}}fmt.Errorf("query {{.MethodName}}: %w", err){{else}}err{{end}}
+		}
+		*dest = append(*dest, {{.Ret.ReturnName}})
+	}
+	if err := rows.Err(); err != nil {
+		return {{if $.WrapErrors}}fmt.Errorf("query {{.MethodName}}: %w", err){{else}}err{{end}}
+	}
+	return nil
+}
+{{- else -}}
 {{- if $.EmitMethodsWithDBArgument -}}
 func (q *Queries) {{.MethodName}}(ctx context.Context, db DBTX, {{.Arg.Pair}}) ([]{{.Ret.DefineType}}, error) {
 	rows, err := db.Query(ctx, {{.ConstantName}}, {{.Arg.Params}})
@@ -77,6 +102,7 @@ func (q *Queries) {{.MethodName}}(ctx context.Context, {{.Arg.Pair}}) ([]{{.Ret.
 	}
 	return items, nil
 }
+{{- end}}
 {{end}}
 
 {{if eq .Cmd ":exec"}}