自定义的类型，定义如下
type Datetime time.Time
````
下面是模型中属性的定义
```go
CreateTime common.Datetime `json:"createTime" gorm:"column:create_time;type:datetime;default:CURRENT_TIMESTAMP;comment:'创建时间';autoCreateTime"`
UpdateTime common.Datetime `json:"updateTime" gorm:"column:update_time;type:datetime;default:CURRENT_TIMESTAMP;comment:'更新时间';autoUpdateTime"`
使用db.AutoMigrate进行数据库迁移时，会自动忽略这两个属性。
Comment From: github-actions[bot]
The issue has been automatically marked as stale as it missing playground pull request link, which is important to help others understand your issue effectively and make sure the issue hasn't been fixed on latest master, checkout https://github.com/go-gorm/playground for details. it will be closed in 30 days if no further activity occurs. if you are asking question, please use the Question template, most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ Search Before Asking ✨
Comment From: github-actions[bot]
The issue has been automatically marked as stale as it missing playground pull request link, which is important to help others understand your issue effectively and make sure the issue hasn't been fixed on latest master, checkout https://github.com/go-gorm/playground for details. it will be closed in 30 days if no further activity occurs. if you are asking question, please use the Question template, most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ Search Before Asking ✨