Go学习笔记：go 操作mysql和Redis

1. go 操作mysql

1.1 表准备

CREATE TABLE `user` (`user_id` int(11) NOT NULL AUTO_INCREMENT,`username` varchar(255) DEFAULT NULL,`sex` varchar(255) DEFAULT NULL,`email` varchar(255) DEFAULT NULL,PRIMARY KEY (`user_id`)) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

mysql的前置知识，我们这里就不讲了，可自行去学习mysql教程

1.2 insert操作

首先，需要引入mysql驱动

_ "github.com/go-sql-driver/mysql"

package mainimport ("database/sql""fmt"_ "github.com/go-sql-driver/mysql""log""time"
)
var DB *sql.DB
func init()  {db,err := sql.Open("mysql","root:root@tcp(localhost:3306)/go_learn")if err != nil {panic(err)}//最大空闲连接数，默认不配置，是2个最大空闲连接db.SetMaxIdleConns(5)//最大连接数，默认不配置，是不限制最大连接数db.SetMaxOpenConns(100)// 连接最大存活时间db.SetConnMaxLifetime(time.Minute * 3)//空闲连接最大存活时间db.SetConnMaxIdleTime(time.Minute * 1)err = db.Ping()if err != nil {log.Println("数据库连接失败")db.Close()panic(err)}DB = db}func save()  {r,err := DB.Exec("insert into user (username,sex,email) values(?,?,?)","test001","man","001@test.com")if err != nil {log.Println("执行sql语句出错")panic(err)}id, err := r.LastInsertId()if err != nil {panic(err)}fmt.Println("插入成功:",id)
}
func main()  {defer DB.Close()save()
}

1.3 Select操作

type User struct {UserId   int    `db:"user_id"`Username string `db:"username"`Sex      string `db:"sex"`Email    string `db:"email"`
}func query(id int)  (*User,error) {rows, err := DB.Query("select * from user where user_id=? limit 1", id)if err != nil{log.Println("查询出现错误:",err)return nil,errors.New(err.Error())}user := new(User)for rows.Next() {if err := rows.Scan(&user.UserId,&user.Username,&user.Sex,&user.Email); err != nil{log.Println("scan error:",err)return nil,errors.New(err.Error())}}return user,nil
}

1.4 Update

func update(username string, id int)  {ret, err := DB.Exec("update user set username=? where user_id=?", username, id)if err != nil {log.Println("更新出现问题:",err)return}affected, _ := ret.RowsAffected()fmt.Println("更新成功的行数:",affected)
}

1.5 Delete

func delete(id int)  {ret, err := DB.Exec("delete from user where user_id=?", id)if err != nil {log.Println("删除出现问题:",err)return}affected, _ := ret.RowsAffected()fmt.Println("删除成功的行数:",affected)
}

1.6 事务

mysql事务特性：

1. 原子性
2. 一致性
3. 隔离性
4. 持久性

func insertTx(username string)  {tx, err := DB.Begin()if err != nil {log.Println("开启事务错误:",err)return}ret, err := tx.Exec("insert into user (username,sex,email) values (?,?,?)", username, "man", "test@test.com")if err != nil {log.Println("事务sql执行出错:",err)return}id, _ := ret.LastInsertId()fmt.Println("插入成功:",id)if username == "lisi" {fmt.Println("回滚...")_ = tx.Rollback()}else {_ = tx.Commit()}}

2. go操作Redis

redis不另行介绍，默认会，如果不了解，先去学习redis教程

安装：go get github.com/go-redis/redis/v8

package mainimport ("context""fmt""github.com/go-redis/redis/v8"
)func main()  {ctx := context.Background()rdb := redis.NewClient(&redis.Options{Addr:	  "localhost:6379",Password: "", // no password setDB:		  0,  // use default DB})err := rdb.Set(ctx, "key", "value", 0).Err()if err != nil {panic(err)}val, err := rdb.Get(ctx, "key").Result()if err != nil {panic(err)}fmt.Println("key", val)val2, err := rdb.Get(ctx, "key2").Result()if err == redis.Nil {fmt.Println("key2 does not exist")} else if err != nil {panic(err)} else {fmt.Println("key2", val2)}
}