go 操作数据库

Posted 2020-11-03 esiarp

假设有了数据库,创建表

CREATE TABLE `userinfo` (
	`uid` INT(10) NOT NULL AUTO_INCREMENT,        //自增字段
	`username` VARCHAR(64) NULL DEFAULT NULL,      //默认值
	`department` VARCHAR(64) NULL DEFAULT NULL,
	`created` DATE NULL DEFAULT NULL,
	PRIMARY KEY (`uid`)            //主键
);

CREATE TABLE `userdetail` (
	`uid` INT(10) NOT NULL DEFAULT ‘0‘,
	`intro` TEXT NULL,
	`profile` TEXT NULL,
	PRIMARY KEY (`uid`)
)

go中操作数据库与python不一样,go没有提供数据库驱动,但提供了接口,我们可以根据接口开发驱动,或是使用第三方库

先来看mysql数据库的

package main

import (
	"database/sql"
	"fmt"
	//"time"

	_ "github.com/go-sql-driver/mysql"   //第三方库,前面加了下划线运行Init函数配置接口.
)

func main() {
	db, err := sql.Open("mysql", "admin:[email protected](127.0.0.1:3306)/haha?charset=utf8")  //open函数用来打开一个注册过的数据库驱动.格式:user:[email protected](localhost:5555)/dbname?charest=utf8                                                                              
	checkErr(err)

	//插入数据
	stmt, err := db.Prepare("INSERT userinfo SET username=?,department=?,created=?") //准备sql要执行的操作,然后返回准备完毕的状态
	checkErr(err)

	res, err := stmt.Exec("a", "研发部门", "2018-1-09")//执行准备好的sql语句
	checkErr(err)

	id, err := res.LastInsertId()//自增ID
	checkErr(err)

	fmt.Println(id)
	//更新数据
	stmt, err = db.Prepare("update userinfo set username=? where uid=?")
	checkErr(err)

	res, err = stmt.Exec("astaxieupdate", id)
	checkErr(err)

	affect, err := res.RowsAffected()
	checkErr(err)

	fmt.Println(affect)

	//查询数据
	rows, err := db.Query("SELECT * FROM userinfo")  //执行返回结果
	checkErr(err)

	for rows.Next() {
		var uid int
		var username string
		var department string
		var created string
		err = rows.Scan(&uid, &username, &department, &created)
		checkErr(err)
		fmt.Println(uid)
		fmt.Println(username)
		fmt.Println(department)
		fmt.Println(created)
	}

	//删除数据
	stmt, err = db.Prepare("delete from userinfo where uid=?")
	checkErr(err)

	res, err = stmt.Exec(id)
	checkErr(err)

	affect, err = res.RowsAffected()
	checkErr(err)

	fmt.Println(affect)

	db.Close()

}

func checkErr(err error) {
	if err != nil {
		panic(err)
	}
}

 

//https://github.com/mattn/go-sqlite3驱动   
func init() {             //以上数据库都是以sql.Register注册的
	sql.Register("sqlite3", &SQLiteDriver{})
}

//https://github.com/mikespook/mymysql驱动
// Driver automatically registered in database/sql
var d = Driver{proto: "tcp", raddr: "127.0.0.1:3306"}
func init() {
	Register("SET NAMES utf8")
	sql.Register("mymysql", &d)
}

sqlite3操作与上面代码基本一致.也需要引入第三方库,在MYSQL中使用?号传递数据,而PostgreSQL是通过$1,$2这种方式来指定要传递的参数