if err != nil {
		t.Fatalf("failed to connect database, got error %v", err)
	}

	dialectors := map[string]bool{"sqlite": true, "postgres": true, "gaussdb": true, "mysql": true, "sqlserver": true}
	if supported, found := dialectors[db.Dialector.Name()]; !(found && supported) {
		return
	}

	DB.Migrator().DropTable(&City{})

	if err = db.AutoMigrate(&City{}); err != nil {

	sql := DB.Dialector.Explain(stmt.SQL.String(), stmt.Vars...)
	if !regexp.MustCompile(`.*age.*=8,`).MatchString(sql) {
		t.Errorf("Failed to generate sql, got %v", sql)
	}

	stmt = dryRunDB.Model(&user).Where("id = ?", 1).Updates(map[string]interface{}{"age": ageUint64(10241024)}).Statement
	sql = DB.Dialector.Explain(stmt.SQL.String(), stmt.Vars...)

	. "gorm.io/gorm/utils/tests"
)

func TestGaussDBReturningIDWhichHasStringType(t *testing.T) {
	t.Skipf("This test case skipped, because of gaussdb not support pgcrypto extension and gen_random_uuid() function")
	if DB.Dialector.Name() != "gaussdb" {
		t.Skip()
	}

	type Yasuo struct {
		// TODO: function gen_random_uuid() does not exist
		ID        string `gorm:"default:gen_random_uuid()"`
		Name      string

	PropagateUnscoped bool

	// ClauseBuilders clause builder
	ClauseBuilders map[string]clause.ClauseBuilder
	// ConnPool db conn pool
	ConnPool ConnPool
	// Dialector database dialector
	Dialector
	// Plugins registered plugins
	Plugins map[string]Plugin

	callbacks  *callbacks
	cacheStore *sync.Map
}

// Apply update config to new config
func (c *Config) Apply(config *Config) error {

		}
	}
}

// only sqlite, postgres, gaussdb, sqlserver support returning
func TestSoftDeleteReturning(t *testing.T) {
	if DB.Dialector.Name() != "sqlite" && DB.Dialector.Name() != "postgres" && DB.Dialector.Name() != "gaussdb" && DB.Dialector.Name() != "sqlserver" {
		return
	}

	users := []*User{
		GetUser("delete-returning-1", Config{}),
		GetUser("delete-returning-2", Config{}),

			t.Fatalf("Failed to find index for many2many for %v %v", indexes[0], indexes[1])
		}
	}
}

func TestAutoMigrateInt8PGAndGaussDB(t *testing.T) {
	if DB.Dialector.Name() != "postgres" && DB.Dialector.Name() != "gaussdb" {
		return
	}

	type Smallint int8

	type MigrateInt struct {
		Int8 Smallint
	}

	tracer := Tracer{
		Logger: DB.Config.Logger,

	if name := DB.Dialector.Name(); name == "sqlite" || name == "sqlserver" {
		t.Skip("skip sqlite, sqlserver due to it doesn't support multiple primary keys with auto increment")
	}

	if name := DB.Dialector.Name(); name == "postgres" {
		t.Skip("skip postgres due to it only allow unique constraint matching given keys")
	}
	if name := DB.Dialector.Name(); name == "gaussdb" {

        setFlags2(config.getFlags2());

        if (config.getMinimumVersion().isSMB2()) {
            this.dialects = new String[] { "SMB 2.???", "SMB 2.002" };
        } else if (config.getMaximumVersion().isSMB2()) {
            this.dialects = new String[] { "NT LM 0.12", "SMB 2.???", "SMB 2.002" };
        } else {
            this.dialects = new String[] { "NT LM 0.12" };
        }
    }

    /**
     * {@inheritDoc}
     *

		t.Fatalf("failed to nested preload")
	}

	if DB.Dialector.Name() == "mysql" {
		// mysql 5.7 doesn't support row_number()
		if strings.HasPrefix(DB.Dialector.(*mysql.Dialector).ServerVersion, "5.7") {
			return
		}
	}
	if DB.Dialector.Name() == "sqlserver" {
		// sqlserver doesn't support order by in subquery
		return
	}

		writer.WriteByte(')')
	case clause.Expr:
		v.Build(stmt)
	case string:
		stmt.DB.Dialector.QuoteTo(writer, v)
	case []string:
		writer.WriteByte('(')
		for idx, d := range v {
			if idx > 0 {
				writer.WriteByte(',')
			}
			stmt.DB.Dialector.QuoteTo(writer, d)
		}
		writer.WriteByte(')')
	default:
		stmt.DB.Dialector.QuoteTo(writer, fmt.Sprint(field))
	}
}

// Quote returns quoted value