Golang使用MySQL

数据库创建demo表

CREATE TABLE `demo` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键',
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '名称',
  `age` tinyint(3) unsigned NOT NULL DEFAULT '0' COMMENT '年龄',
  `sex` tinyint(1) unsigned NOT NULL DEFAULT '1' COMMENT '性别：1男，2女',
  `mobile` char(11) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '手机号',
  `email` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '邮箱',
  `qq` int(11) unsigned NOT NULL COMMENT 'QQ',
  `is_delete` tinyint(1) unsigned NOT NULL DEFAULT '1' COMMENT '是否删除：1正常，2删除',
  `status` tinyint(1) unsigned NOT NULL DEFAULT '1' COMMENT '状态：1正常，2禁用，3异常。。。',
  PRIMARY KEY (`id`),
  UNIQUE KEY `id` (`id`) USING BTREE COMMENT '唯一主键'
) ENGINE=InnoDB AUTO_INCREMENT=38 DEFAULT CHARSET=utf8 COMMENT='用户表';

创建DB连接，创建结构体Demo

import (
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"time"
)

var MysqlDb *sql.DB
var Err error

const (
	USERNAME = ""
	PASSWORD = ""
	HOST      = ""
	PORT      = ""
	DATABASE  = ""
	CHARSET   = ""
)

func init() {
	dbDSN := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=%s", USERNAME, PASSWORD, HOST, PORT, DATABASE, CHARSET)
	// 打开连接失败
	MysqlDb, Err = sql.Open("mysql", dbDSN)
	if Err != nil {
		panic("数据源配置错误: " + Err.Error())
	}
	// 最大连接数
	MysqlDb.SetMaxOpenConns(100)
	// 闲置连接数
	MysqlDb.SetMaxIdleConns(20)
	// 最大连接周期
	MysqlDb.SetConnMaxLifetime(100 * time.Second)
	if Err = MysqlDb.Ping(); nil != Err {
		panic("数据库链接失败: " + Err.Error())
	}
	// defer MysqlDb.Close();
}

type Demo struct {
	Id int `json:"id"`
	Name string `json:"name"`
	Age int `json:"age"`
	Status int `json:"status"`
	Sex int `json:"sex"`
	Email string `json:"email"`
	Mobile string `json:"mobile"`
	Qq string `json:"qq"`
}

使用QueryRow查询

func MysqlQueryRow() {
	var demo Demo
	// 查询 QueryRow 返回一条
	row := MysqlDb.QueryRow("SELECT `id`, `name` FROM  demo WHERE `status` = ?", 1)
	Err = row.Scan(&demo.Id, &demo.Name)
	if Err == nil {
		fmt.Println(demo.Name, demo.Id)
	} else {
		fmt.Println(Err.Error())
	}
}

使用Query查询

func MysqlQuery() {
	// 查询 Query
	var demos []Demo
	var demo Demo
	rows, Err := MysqlDb.Query("SELECT `id`, `name` FROM  demo WHERE `status` = ?", 1)
	if Err == nil {
		// 依次循环取
		for rows.Next() {
			rows.Scan(&demo.Id, &demo.Name)
			demos = append(demos, demo)
		}
		fmt.Println(demos)
	} else {
		fmt.Println(Err.Error())
	}
}

新增INSERT

func MysqlInsert() {
	res, Err := MysqlDb.Exec("INSERT INTO demo(`name`, `age`, `status`, `sex`, `email`, `mobile`, `qq`) " +
		"VALUES(?, ?, ?, ?, ?, ?, ?)", "孙策", "20", "2", "1", "[email protected]", "13366666666", "555333999")
	if Err == nil {
		// 获取最后插入ID
		num, Err := res.LastInsertId()
		if Err == nil {
			fmt.Println(num)
		} else {
			fmt.Println(Err.Error())
		}
	} else {
		fmt.Println(Err.Error())
	}
}

更新UPDATE

func MysqlUpdate() {
	res, Err := MysqlDb.Exec("UPDATE demo SET `name` = ? WHERE `id` = ?","马超", 1)
	if Err == nil {
		// 获取影响行
		num, Err := res.RowsAffected()
		if Err == nil {
			fmt.Println(num)
		} else {
			fmt.Println(Err.Error())
		}
	} else {
		fmt.Println(Err.Error())
	}
}

删除DELETE

func MysqlDelete() {
	res, Err := MysqlDb.Exec("DELETE FROM demo WHERE `id` = ?", 37)
	if Err == nil {
		// 获取影响行
		num, Err := res.RowsAffected()
		if Err == nil {
			fmt.Println(num)
		} else {
			fmt.Println(Err.Error())
		}
	} else {
		fmt.Println(Err.Error())
	}
}

事务处理

func MysqlTx() {
	// 开启事务
	tx, Err := MysqlDb.Begin()
	if Err == nil {
		res1, _ := tx.Exec("UPDATE demo SET `name` = ? WHERE `id` = ?","赵云", 35)
		res2, _ := tx.Exec("UPDATE demo SET `name` = ? WHERE `id` = ?","赵云", 38)
		num1, _ := res1.RowsAffected()
		num2, _ := res2.RowsAffected()
		if num1 > 0 && num2 > 0{
			// 提交
			Err = tx.Commit()
			if Err == nil {
				fmt.Println("Success")
			} else {
				fmt.Println(Err.Error())
			}
		} else {
			// 回滚
			Err = tx.Rollback()
			if Err == nil {
				fmt.Println("Fail")
			} else {
				fmt.Println(Err.Error())
			}
		}
	} else {
		fmt.Println(Err.Error())
	}
}