design_quantity/datasource/dbhelper.go

/*
 * @description:
 * @Author: CP
 * @Date: 2020-08-20 22:25:17
 * @FilePath: \construction_management\datasource\dbhelper.go
 */
package datasource

import (
	"fmt"
	"log"
	"sync"

	_ "github.com/go-sql-driver/mysql"
	"github.com/go-xorm/xorm"
	"go.mod/conf"
)

//互斥锁
var dbLock sync.Mutex
var masterInstance *xorm.Engine

//单例模式
func InstanceDbMaster() *xorm.Engine {
	if masterInstance != nil {
		return masterInstance
	}
	dbLock.Lock()
	defer dbLock.Unlock()
	if masterInstance != nil {
		return masterInstance
	}
	return NewDbMaster()
}

func NewDbMaster() *xorm.Engine {
	sourcename := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8",
		conf.DbMaster.User,
		conf.DbMaster.Pwd,
		conf.DbMaster.Host,
		conf.DbMaster.Port,
		conf.DbMaster.Datebase)
	instance, err := xorm.NewEngine(conf.DriverName, sourcename)
	if err != nil {
		log.Fatal("dbhelper.NewDbMaster NewEngine error ", err)
		return nil
	}
	//展示执行的sql语句
	instance.ShowSQL(true)
	masterInstance = instance
	return instance
}