接上文，前边我们了解了关于基本代码生成以及schema 迁移的学习，下边我们看看基本的数据操作
参考代码： https://github.com/rongfengliang/ent-demo
环境准备
- mysql 数据库
使用docker-compose 运行
version: "3"
services:
mysql:
image: mysql:5.7.16
ports:
- 3306:3306
command: --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
environment:
MYSQL_ROOT_PASSWORD: dalongrong
MYSQL_DATABASE: gogs
MYSQL_USER: gogs
MYSQL_PASSWORD: dalongrong
TZ: Asia/Shanghai
- go mod 项目
go mod github.com/rongfengliang/ent-demo
- 项目约定
为了方便测试，使用多main 入口，同时使用makefile 进行管理
项目结构
├── Makefile
├── README.md
├── build
│ ├── create
│ ├── migration
│ └── query
├── cmd
│ ├── create
│ │ └── main.go
│ ├── migration
│ │ └── main.go
│ └── query
│ └── main.go
├── docker-compose.yaml
├── ent
│ ├── client.go
│ ├── config.go
│ ├── context.go
│ ├── ent.go
│ ├── example_test.go
│ ├── migrate
│ │ ├── migrate.go
│ │ └── schema.go
│ ├── predicate
│ │ └── predicate.go
│ ├── schema
│ │ └── user.go
│ ├── tx.go
│ ├── user
│ │ ├── user.go
│ │ └── where.go
│ ├── user.go
│ ├── user_create.go
│ ├── user_delete.go
│ ├── user_query.go
│ └── user_update.go
├── go.mod
└── go.sum
说明
cmd 目录为操作，ent 为代码生成
Makefile
.PHONY : clean
all: clean cli
clean:
rm -rf build/*
cli:
go build -o build ./cmd/...
常见数据处理
- schmma 处理
这个不是必须，如果项目已经运行过 ，可以不用运行 ，首次运行的话需要添加
go run cmd/migration/main.go
- 添加数据操作
cmd/create/main.go
package main
import (
"context"
"fmt"
"log"
_ "github.com/go-sql-driver/mysql"
"github.com/rongfengliang/ent-demo/ent"
)
func main() {
client, err := ent.Open("mysql", "root:dalongrong@tcp(127.0.0.1)/gogs")
if err != nil {
log.Fatalf("failed opening connection to sqlite: %v", err)
}
defer client.Close()
ctx := context.Background()
createUser(ctx, client)
}
func createUser(ctx context.Context, client *ent.Client) (*ent.User, error) {
u, err := client.User.
Create().
SetAge(30).
SetName("a8m").
Save(ctx)
if err != nil {
return nil, fmt.Errorf("failed creating user: %v", err)
}
log.Println("user was created: ", u)
return u, nil
}
说明：
从上边可以看出，使用很简单
- 运行效果
go run cmd/create/main.go
2019/10/14 13:53:20 user was created: User(id=5, age=30, name=a8m)
➜ first git:(master) ✗
数据查询处理
- 查询代码
cmd/query/main.go
package main
import (
"context"
"fmt"
"log"
_ "github.com/go-sql-driver/mysql"
"github.com/rongfengliang/ent-demo/ent"
"github.com/rongfengliang/ent-demo/ent/user"
)
func main() {
client, err := ent.Open("mysql", "root:dalongrong@tcp(127.0.0.1)/gogs")
if err != nil {
log.Fatalf("failed opening connection to sqlite: %v", err)
}
defer client.Close()
ctx := context.Background()
queryUser(ctx, client)
}
func queryUser(ctx context.Context, client *ent.Client) (*ent.User, error) {
u, err := client.User.
Query().
Where(user.ID(1)).
// `Only` fails if no user found,
// or more than 1 user returned.
Only(ctx)
if err != nil {
return nil, fmt.Errorf("failed querying user: %v", err)
}
log.Println("user returned: ", u)
return u, nil
}
- 运行效果
go run cmd/query/main.go
2019/10/14 13:54:49 user returned: User(id=1, age=30, name=a8m)
说明
以上是一个简单的insert 以及查询处理，后边会介绍下关于图查询的处理,实际上ent 还包含了数据校验的处理
参考资料
https://entgo.io/docs/getting-started/
https://github.com/rongfengliang/ent-demo