feat: "skipupdate" model field tag (#565)

* feat: "skipupdate" model field tag

internal/dbtest/db_test.go

@@ -12,6 +12,7 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/uptrace/bun"
 	"github.com/uptrace/bun/dialect"
@@ -266,6 +267,7 @@ func TestDB(t *testing.T) {
 		{testBinaryData},
 		{testUpsert},
 		{testMultiUpdate},
+		{testUpdateWithSkipupdateTag},
 		{testTxScanAndCount},
 		{testEmbedModelValue},
 		{testEmbedModelPointer},
@@ -1247,6 +1249,48 @@ func testMultiUpdate(t *testing.T, db *bun.DB) {
 	require.NoError(t, err)
 }
 
+func testUpdateWithSkipupdateTag(t *testing.T, db *bun.DB) {
+	type Model struct {
+		ID        int64 `bun:",pk,autoincrement"`
+		Name      string
+		CreatedAt time.Time `bun:",skipupdate"`
+	}
+
+	ctx := context.Background()
+
+	err := db.ResetModel(ctx, (*Model)(nil))
+	require.NoError(t, err)
+
+	createdAt := time.Now().Truncate(time.Minute).UTC()
+
+	model := &Model{ID: 1, Name: "foo", CreatedAt: createdAt}
+
+	_, err = db.NewInsert().Model(model).Exec(ctx)
+	require.NoError(t, err)
+	require.NotZero(t, model.CreatedAt)
+
+	//
+	// update field with tag "skipupdate"
+	//
+	model.CreatedAt = model.CreatedAt.Add(2 * time.Minute)
+	_, err = db.NewUpdate().Model(model).WherePK().Exec(ctx)
+	require.NoError(t, err)
+
+	//
+	// check
+	//
+	model_ := new(Model)
+	model_.ID = model.ID
+	err = db.NewSelect().Model(model_).WherePK().Scan(ctx)
+	require.NoError(t, err, "select")
+	require.NotEmpty(t, model_)
+	require.Equal(t, model.ID, model_.ID)
+	require.Equal(t, model.Name, model_.Name)
+	require.Equal(t, createdAt.UTC(), model_.CreatedAt.UTC())
+
+	require.NotEqual(t, model.CreatedAt.UTC(), model_.CreatedAt.UTC())
+}
+
 func testTxScanAndCount(t *testing.T, db *bun.DB) {
 	type Model struct {
 		ID  int64 `bun:",pk,autoincrement"`

internal/dbtest/pg_test.go

@@ -646,3 +646,48 @@ func TestPostgresHStoreQuote(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, wanted, m)
 }
+
+func TestPostgresSkipupdateField(t *testing.T) {
+	type Model struct {
+		ID        int64 `bun:",pk,autoincrement"`
+		Name      string
+		CreatedAt time.Time `bun:",skipupdate"`
+	}
+
+	ctx := context.Background()
+
+	db := pg(t)
+	defer db.Close()
+
+	err := db.ResetModel(ctx, (*Model)(nil))
+	require.NoError(t, err)
+
+	createdAt := time.Now().Truncate(time.Minute).UTC()
+
+	model := &Model{ID: 1, Name: "foo", CreatedAt: createdAt}
+
+	_, err = db.NewInsert().Model(model).Exec(ctx)
+	require.NoError(t, err)
+	require.NotZero(t, model.CreatedAt)
+
+	//
+	// update field with tag "skipupdate"
+	//
+	model.CreatedAt = model.CreatedAt.Add(2 * time.Minute)
+	_, err = db.NewUpdate().Model(model).WherePK().Exec(ctx)
+	require.NoError(t, err)
+
+	//
+	// check
+	//
+	model_ := new(Model)
+	model_.ID = model.ID
+	err = db.NewSelect().Model(model_).WherePK().Scan(ctx)
+	require.NoError(t, err, "select")
+	require.NotEmpty(t, model_)
+	require.Equal(t, model.ID, model_.ID)
+	require.Equal(t, model.Name, model_.Name)
+	require.Equal(t, createdAt.UTC(), model_.CreatedAt.UTC())
+
+	require.NotEqual(t, model.CreatedAt.UTC(), model_.CreatedAt.UTC())
+}

query_update.go

@@ -273,6 +273,10 @@ func (q *UpdateQuery) appendSetStruct(
 	isTemplate := fmter.IsNop()
 	pos := len(b)
 	for _, f := range fields {
+		if f.SkipUpdate() {
+			continue
+		}
+
 		app, hasValue := q.modelValues[f.Name]
 
 		if !hasValue && q.omitZero && f.HasZeroValue(model.strct) {

schema/field.go

@@ -120,6 +120,10 @@ func (f *Field) ScanValue(strct reflect.Value, src interface{}) error {
 	return f.ScanWithCheck(fv, src)
 }
 
+func (f *Field) SkipUpdate() bool {
+	return f.Tag.HasOption("skipupdate")
+}
+
 func indexEqual(ind1, ind2 []int) bool {
 	if len(ind1) != len(ind2) {
 		return false

schema/table.go

@@ -901,6 +901,7 @@ func isKnownFieldOption(name string) bool {
 		"unique",
 		"soft_delete",
 		"scanonly",
+		"skipupdate",
 
 		"pk",
 		"autoincrement",