【golang】gorm migration建表

package dao

import (
	"fmt"
	"mall/model"
)

func migration() {
	err := _db.Set("grom:table_options", "charset=utf8mb4").
		AutoMigrate(
			&model.User{},
			&model.Address{},
			&model.Admin{},
		)
	if err != nil {
		fmt.Println("err", err)
	}

}

package dao

import (
	"context"
	"time"

	"github.com/gin-gonic/gin"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
	"gorm.io/gorm/schema"
	"gorm.io/plugin/dbresolver"
)

var _db *gorm.DB

func Database(connRead, connWrite string) {
	//1.配置日志
	var ormLogger logger.Interface
	if gin.Mode() == "debug" {
		//默认
		ormLogger = logger.Default.LogMode(logger.Info)
	} else {
		ormLogger = logger.Default
	}
	//2.gorm 连接mysql数据库
	db, err := gorm.Open(mysql.New(mysql.Config{
		DSN:                       connRead,
		DefaultStringSize:         256,  //string类型字段默认长度
		DisableDatetimePrecision:  true, //进展datatime精度 5.6之前的数据库不支持
		DontSupportRenameIndex:    true, //重命名索引，就要把索引先删掉再重建，mysql5,。7不支持
		DontSupportRenameColumn:   true, //用change重命名索引，mysql 8之前不支持
		SkipInitializeWithVersion: false,
	}), &gorm.Config{
		Logger: ormLogger,
		NamingStrategy: schema.NamingStrategy{
			//命名策略不加s
			SingularTable: true,
		},
	})

	if err != nil {
		return
	}
	sqlDB, _ := db.DB()
	sqlDB.SetMaxOpenConns(20) //设置连接池
	sqlDB.SetMaxOpenConns(100)
	sqlDB.SetConnMaxLifetime(time.Second * 30)
	_db = db

	//3.主从配置
	_db.Use(dbresolver.
		Register(dbresolver.Config{
			Sources:  []gorm.Dialector{mysql.Open(connWrite)},                       //写
			Replicas: []gorm.Dialector{mysql.Open(connRead), mysql.Open(connWrite)}, //读
			Policy:   dbresolver.RandomPolicy{},
		}))
	migration()
}

func NewDBClient(ctx context.Context) *gorm.DB {
	db := _db
	return db.WithContext(ctx)
}

package conf

import (
	"mall/dao"
	"strings"

	"gopkg.in/go-ini/ini.v1"
)

var (
	AppModel string
	HttpPort string

	Db         string
	DbHost     string
	DbPort     string
	DbUser     string
	DbPassword string
	DbName     string




)

func Init() {
	//本地读取环境变量
	file, err := ini.Load("./conf/config.ini")
	if err != nil {
		panic(err)
	}
	LoadMysql(file)

	//mysql读写分离
	//mysql 读(8) 作为主
	pathRead := strings.Join([]string{DbUser, ":", DbPassword, "@tcp(", DbHost, ":", DbPort, ")/", DbName, "?charset=utf8mb4&parseTime=true"}, "")
	//mysql 写(2) 作为从 主从复制
	pathWrite := strings.Join([]string{DbUser, ":", DbPassword, "@tcp(", DbHost, ":", DbPort, ")/", DbName, "?charset=utf8mb4&parseTime=true"}, "")
	//传入dao层
	dao.Database(pathRead, pathWrite)
}



func LoadMysql(file *ini.File) {
	Db = file.Section("mysql").Key("DB").String()
	DbHost = file.Section("mysql").Key("DbHost").String()
	DbPort = file.Section("mysql").Key("DbPort").String()
	DbUser = file.Section("mysql").Key("DbUser").String()
	DbPassword = file.Section("mysql").Key("DbPassword").String()
	DbName = file.Section("mysql").Key("DbName").String()

}