ent 基本使用九 代码生成

ent 提供了cli 工具，可以方便我们进行schema 以及代码生成，同时目前提供的cli已经够用了

安装 cli

go get github.com/facebookincubator/ent/cmd/entc

创建schema

entc init User Pet

生成代码

基于schema 的定义（字段，索引，边，配置）

entc generate ./ent/schema

说明：
生成的代码包含了crud、migrate、entity、client

版本兼容处理

使用独立的cli以及生成的代码，可能会和我们的框架不兼容 ，处理方法使用go:generate
参考配置：

package ent

​

//go:generate go run github.com/facebookincubator/ent/cmd/entc generate ./schema

 

代码生成选项

• 命令参数

generate go code for the schema directory

​

Usage:

  entc generate [flags] path

​

Examples:

  entc generate ./ent/schema

  entc generate github.com/a8m/x

​

Flags:

      --header string override codegen header

  -h, --help help for generate

      --idtype [int string] type of the id field (default int)

      --storage strings list of storage drivers to support (default [sql])

      --target string target directory for codegen

      --template strings external templates to execute

 

 

• 存储配置
  目前ent 生成可以支持sql方言以及Gremlin方言，后期应该还会扩展的
• 外部模版
  当前官方提供了一个graphql 的 demo

entc 做为包依赖

entc 可以做为一个包在我们的项目中使用

 

package main

​

import (

    "log"

​

    "github.com/facebookincubator/ent/entc"

    "github.com/facebookincubator/ent/entc/gen"

    "github.com/facebookincubator/ent/schema/field"

)

​

func main() {

    err := entc.Generate("./schema", &gen.Config{

        Header: "// Your Custom Header",

        IDType: &field.TypeInfo{Type: field.TypeInt},

    })

    if err != nil {

        log.Fatal("running ent codegen:", err)

    }

}

 

 

查看schema 的描述信息

• 命令

entc describe ./ent/schema

• 参考

City:

        +-------+--------+--------+----------+----------+---------+---------------+-----------+-----------------------+------------+

        | Field | Type | Unique | Optional | Nillable | Default | UpdateDefault | Immutable | StructTag | Validators |

        +-------+--------+--------+----------+----------+---------+---------------+-----------+-----------------------+------------+

        | id | <nil> | false | false | false | false | false | false | json:"id,omitempty" | 0 |

        | name | string | false | false | false | false | false | false | json:"name,omitempty" | 0 |

        +-------+--------+--------+----------+----------+---------+---------------+-----------+-----------------------+------------+

        +---------+--------+---------+---------+----------+--------+----------+

        | Edge | Type | Inverse | BackRef | Relation | Unique | Optional |

        +---------+--------+---------+---------+----------+--------+----------+

        | streets | Street | false | | O2M | false | true |

        +---------+--------+---------+---------+----------+--------+----------+

​

Street:

        +-------+--------+--------+----------+----------+---------+---------------+-----------+-----------------------+------------+

        | Field | Type | Unique | Optional | Nillable | Default | UpdateDefault | Immutable | StructTag | Validators |

        +-------+--------+--------+----------+----------+---------+---------------+-----------+-----------------------+------------+

        | id | <nil> | false | false | false | false | false | false | json:"id,omitempty" | 0 |

        | name | string | false | false | false | false | false | false | json:"name,omitempty" | 0 |

        +-------+--------+--------+----------+----------+---------+---------------+-----------+-----------------------+------------+

        +------+------+---------+---------+----------+--------+----------+

        | Edge | Type | Inverse | BackRef | Relation | Unique | Optional |

        +------+------+---------+---------+----------+--------+----------+

        | city | City | true | streets | M2O | true | true |

        +------+------+---------+---------+----------+--------+----------+

参考资料

https://entgo.io/docs/code-gen/