ent 基本使用六 Mixin

ent 的Mixin 可以让我们服用已有的schema

Mixin 接口说明

type Mixin interface {
    Fields() []ent.Field
}

一个demo

  • 代码
// -------------------------------------------------
// Mixin definition
// TimeMixin implements the ent.Mixin for sharing
// time fields with package schemas.
type TimeMixin struct{}
func (TimeMixin) Fields() []ent.Field {
    return []ent.Field{
        field.Time("created_at").
            Immutable().
            Default(time.Now),
        field.Time("updated_at").
            Default(time.Now).
            UpdateDefault(time.Now),
    }
}
// DetailsMixin implements the ent.Mixin for sharing
// entity details fields with package schemas.
type DetailsMixin struct{}
func (DetailsMixin) Fields() []ent.Field {
    return []ent.Field{
        field.Int("age").
            Positive(),
        field.String("name").
            NotEmpty(),
    }
}
// -------------------------------------------------
// Schema definition
// User schema mixed-in the TimeMixin and DetailsMixin fields and therefore
// has 5 fields: `created_at`, `updated_at`, `age`, `name` and `nickname`.
type User struct {
    ent.Schema
}
func (User) Mixin() []ent.Mixin {
    return []ent.Mixin{
        TimeMixin{},
        DetailsMixin{},
    }
}
func (User) Fields() []ent.Field {
    return []ent.Field{
        field.String("nickname").
            Unique(),
    }
}
// Pet schema mixed-in the DetailsMixin fields and therefore
// has 3 fields: `age`, `name` and `weight`.
type Pet struct {
    ent.Schema
}
func (Pet) Mixin() []ent.Mixin {
    return []ent.Mixin{
        DetailsMixin{},
    }
}
func (Pet) Fields() []ent.Field {
    return []ent.Field{
        field.Float("weight"),
    }
} 
  • 简单说明
    以上代码实现了DetailsMixin 以及TimeMixin 两个Mixin 我们在User 以及Pet中通过添加 Mixin 方法实现了复用

参考资料

https://entgo.io/docs/schema-mixin/

posted on 2019-10-14 21:13  荣锋亮  阅读(649)  评论(0编辑  收藏  举报

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