c.Build(stmt)
		case clause.Expression:
			v.Build(stmt)
		case driver.Valuer:
			stmt.Vars = append(stmt.Vars, v)
			stmt.DB.Dialector.BindVarTo(writer, stmt, v)
		case []byte:
			stmt.Vars = append(stmt.Vars, v)
			stmt.DB.Dialector.BindVarTo(writer, stmt, v)
		case []interface{}:
			if len(v) > 0 {
				writer.WriteByte('(')
				stmt.AddVar(writer, v...)
				writer.WriteByte(')')
			} else {

func (DummyDialector) DefaultValueOf(field *schema.Field) clause.Expression {
	return clause.Expr{SQL: "DEFAULT"}
}

func (DummyDialector) Migrator(*gorm.DB) gorm.Migrator {
	return nil
}

func (DummyDialector) BindVarTo(writer clause.Writer, stmt *gorm.Statement, v interface{}) {
	writer.WriteByte('?')
}

func (DummyDialector) QuoteTo(writer clause.Writer, str string) {
	var (
		underQuoted, selfQuoted bool

// Dialector GORM database dialector
type Dialector interface {
	Name() string
	Initialize(*DB) error
	Migrator(db *DB) Migrator
	DataTypeOf(*schema.Field) string
	DefaultValueOf(*schema.Field) clause.Expression
	BindVarTo(writer clause.Writer, stmt *Statement, v interface{})
	QuoteTo(clause.Writer, string)
	Explain(sql string, vars ...interface{}) string
}

// Plugin GORM plugin interface
type Plugin interface {
	Name() string

											vars := onStmt.Vars
											for idx, v := range vars {
												bindvar := strings.Builder{}
												onStmt.Vars = vars[0 : idx+1]
												db.Dialector.BindVarTo(&bindvar, &onStmt, v)
												onSQL = strings.Replace(onSQL, bindvar.String(), "?", 1)
											}

											exprs = append(exprs, clause.Expr{SQL: onSQL, Vars: vars})
										}
									}
								}

		if field.DefaultValueInterface != nil {
			defaultStmt := &gorm.Statement{Vars: []interface{}{field.DefaultValueInterface}}
			m.Dialector.BindVarTo(defaultStmt, defaultStmt, field.DefaultValueInterface)
			expr.SQL += " DEFAULT " + m.Dialector.Explain(defaultStmt.SQL.String(), field.DefaultValueInterface)
		} else if field.DefaultValue != "(-)" {