code: func getType(ktype string) (kt, tag string, hasTime bool) {
  	kv := strings.SplitN(ktype, ":", 2)
  	switch kv[0] {
  	case "string":
  		if len(kv) == 2 {
  			return "string", "`orm:\"size(" + kv[1] + ")\"`", false
  		}
  		return "string", "`orm:\"size(128)\"`", false
  	case "text":
  		return "string", "`orm:\"type(longtext)\"`", false
  	case "auto":
  		return "int64", "`orm:\"auto\"`", false
  	case "pk":
  		return "int64", "`orm:\"pk\"`", false
  	case "datetime":
  		return "time.Time", "`orm:\"type(datetime)\"`", true
  	case "int", "int8", "int16", "int32", "int64":
  		fallthrough
  	case "uint", "uint8", "uint16", "uint32", "uint64":
  		fallthrough
  	case "bool":
  		fallthrough
  	case "float32", "float64":
  		return kv[0], "", false
  	case "float":
  		return "float64", "", false
  	}
  	return "", "", false
  }
docs: // fields support type
  // http://beego.me/docs/mvc/model/models.md#mysql