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/