code: func (engine *Engine) formatTime(sqlTypeName string, t time.Time) (v interface{}) {
  	switch sqlTypeName {
  	case core.Time:
  		s := t.Format("2006-01-02 15:04:05") //time.RFC3339
  		v = s[11:19]
  	case core.Date:
  		v = t.Format("2006-01-02")
  	case core.DateTime, core.TimeStamp:
  		v = t.Format("2006-01-02 15:04:05")
  	case core.TimeStampz:
  		if engine.dialect.DBType() == core.MSSQL {
  			v = t.Format("2006-01-02T15:04:05.9999999Z07:00")
  		} else {
  			v = t.Format(time.RFC3339Nano)
  		}
  	case core.BigInt, core.Int:
  		v = t.Unix()
  	default:
  		v = t
  	}
  	return
  }
docs: // formatTime format time as column type