数据的持久化是程序中必不可少的，所以编程语言中对数据库的操作是非常重要的一块，本文介绍Go语言对mysql数据库的操作。
基本操作
建立连接
db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/betting?charset=utf8")errDeal("连接数据库", err)defer db.Close()连接参数一般有以下几种
user@unix(/path/to/socket)/dbname?charset=utf8user:password@tcp(localhost:5555)/dbname?charset=utf8user:password@/dbnameuser:password@tcp([de:ad:be:ef::ca:fe]:80)/dbname
增删改操作
// 插入数据---------------------方法1result, err := db.Exec("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc)" +" VALUES(?,now(),?,?,?)", "admin", "127.0.0.1", "登录", "登录成功")errDeal("插入数据", err)// 查看返回信息count, err := result.RowsAffected()errDeal("查看插入数据条数", err)fmt.Printf("插入数据条数：%d\n", count)id, err := result.LastInsertId()errDeal("查看最后插入数据的id", err)fmt.Printf("最后插入数据的id：%d\n", id)// 插入数据---------------------方法2，先创建一个预处理语句，再执行stmt, err := db.Prepare("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc)" +" VALUES(?,now(),?,?,?)")result1, err1 := stmt.Exec("admin", "127.0.0.1", "登录", "登录成功")errDeal("方法2插入数据", err1)fmt.Println(result1.LastInsertId())// 删除数据result2, err := db.Exec("DELETE FROM admin_log WHERE id=?", 2014)fmt.Println(result2.RowsAffected())// 更新数据result3, err := db.Exec("UPDATE admin_log SET log_ip=? WHERE id=?", "192.168.8.9", 2017)fmt.Println(result3.RowsAffected())单条数据查询
// 先定义存储查询结果的变量var rid intvar username, time, ip, logType stringvar desc, remark, spare interface{} // 如果字段中可能出现值为nil的情况，可以将变量申明为interface{}类型err2 := db.QueryRow("SELECT id,admin_username,log_time,log_ip,log_type,log_desc,remark,spare" + " FROM admin_log WHERE id=?", 2017).Scan(&rid, &username, &time, &ip, &logType, &desc, &remark, &spare) // 传入的是变量的指针errDeal("查询单条数据", err2)fmt.Printf("id=%d,username=%s,time=%s,ip=%s,logType=%s,desc=%s,remark=%v,spare=%v\n", rid, username, time, ip, logType, desc, remark, spare)多条数据查询
// 查询多条数据rows, err3 := db.Query("SELECT admin_username,log_time,log_ip,log_type,log_desc" + " FROM admin_log WHERE id=? OR id=?", 2017, 2019)errDeal("查询多条数据", err3)// 对多条数据进行遍历for rows.Next() { err4 := rows.Scan(&username, &time, &ip, &logType, &desc) errDeal("遍历多条数据", err4) fmt.Printf("username=%s,time=%s,ip=%s,logType=%s,desc=%s\n", username, time, ip, logType, desc)}// 如果查询中不指定具体字段，使用*rows, err33 := db.Query("SELECT *" + " FROM admin_log WHERE id>?", 2017)errDeal("查询多条数据", err33)// 查询所有字段名，返回string切片columes, err333 := rows.Columns()errDeal("rows.Columns()方法调用", err333)fmt.Printf("%T----%v\n", columes, columes)var scanColumes = make([]interface{}, len(columes))var values = make([]interface{}, len(columes))for index, _ := range scanColumes { scanColumes[index] = &values[index]}for rows.Next() { err4 := rows.Scan(scanColumes...) errDeal("遍历多条数据", err4) for i, val := range values { if strings.EqualFold(judgeType(val), "[]uint8") { fmt.Printf("%s(%T)==%s\t", columes[i], val, val) } else { fmt.Printf("%s(%T)==%v\t", columes[i], val, val) } } fmt.Println()}事务
开启事务
// 开启事务，tx是从连接池中取出一个连接，在关闭之前都是使用这个连接，提交事务和回滚事务都是操作txtx, err5 := db.Begin()errDeal("开启事务", err5)_, err6 := tx.Exec("UPDATE admin_log SET log_desc=? WHERE id=?", "测试事务222", 2019)//if err6 != nil {if err6 == nil { tx.Rollback() // 回滚}tx.Commit() // 提交批量插入数据
// 批量数据插入tx, err7 := db.Begin()errDeal("数据批量插入，开启事务", err7)insertValues := [][]interface{}{{"admin", "127.0.0.1", "登录", "登录成功"},{"admin", "127.0.0.1", "删除", "删除数据"},{"admin", "127.0.0.1", "退出", "退出系统"}}stmt, err8 := tx.Prepare("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc) VALUES(?,now(),?,?,?)")errDeal("数据批量插入，预处理", err8)for _, val := range insertValues { _, err := stmt.Exec(val...) if err != nil { fmt.Printf("出现错误回滚，错误信息：%v", err) tx.Rollback() }}tx.Commit()sqlx的使用及批量插入
xdb, err9 := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/betting?charset=utf8")errDeal("sqlx连接数据库", err9)txx, err10 := xdb.Beginx()errDeal("sqlx开启事务", err10)insertValuesx := [][]interface{}{{"admin", "127.0.0.1", "登录", "登录成功X"},{"admin", "127.0.0.1", "删除", "删除数据X"},{"admin", "127.0.0.1", "退出", "退出系统X"}}stmtx, err11 := txx.Preparex("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc) VALUES(?,now(),?,?,?)")errDeal("数据批量插入，预处理", err11)for _, val := range insertValuesx { _, err := stmtx.Exec(val...) if err != nil { fmt.Printf("sqlx出现错误回滚，错误信息：%v", err) txx.Rollback() }}txx.Commit()完整代码
package mainimport ( "database/sql" _"github.com/go-sql-driver/mysql" // 这里很重要，导入自己本地使用的数据库驱动，前面是下划线，否则会报错：sql: unknown driver "mysql" (forgotten import?) "fmt" "strings" "github.com/jmoiron/sqlx")func main() { // 连接数据库，用户名:密码@协议(地址:端口)/数据库?参数=参数值，常用"用户名:密码@tcp(ip:端口)/数据库名?charset=字符集" db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/betting?charset=utf8") errDeal("连接数据库", err) defer db.Close() //=========================================================================================增删改 // 插入数据---------------------方法1 result, err := db.Exec("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc)" + " VALUES(?,now(),?,?,?)", "admin", "127.0.0.1", "登录", "登录成功") errDeal("插入数据", err) // 查看返回信息 count, err := result.RowsAffected() errDeal("查看插入数据条数", err) fmt.Printf("插入数据条数：%d\n", count) id, err := result.LastInsertId() errDeal("查看最后插入数据的id", err) fmt.Printf("最后插入数据的id：%d\n", id) // 插入数据---------------------方法2，先创建一个预处理语句，再执行 stmt, err := db.Prepare("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc)" + " VALUES(?,now(),?,?,?)") result1, err1 := stmt.Exec("admin", "127.0.0.1", "登录", "登录成功") errDeal("方法2插入数据", err1) fmt.Println(result1.LastInsertId()) // 删除数据 result2, err := db.Exec("DELETE FROM admin_log WHERE id=?", 2014) fmt.Println(result2.RowsAffected()) // 更新数据 result3, err := db.Exec("UPDATE admin_log SET log_ip=? WHERE id=?", "192.168.8.9", 2017) fmt.Println(result3.RowsAffected()) //=============================================================================================查询 // 查询单条数据 // 先定义存储查询结果的变量 var rid int var username, time, ip, logType string var desc, remark, spare interface{} // 如果字段中可能出现值为nil的情况，可以将变量申明为interface{}类型 err2 := db.QueryRow("SELECT id,admin_username,log_time,log_ip,log_type,log_desc,remark,spare" + " FROM admin_log WHERE id=?", 2017).Scan(&rid, &username, &time, &ip, &logType, &desc, &remark, &spare) // 传入的是变量的指针 errDeal("查询单条数据", err2) fmt.Printf("id=%d,username=%s,time=%s,ip=%s,logType=%s,desc=%s,remark=%v,spare=%v\n", rid, username, time, ip, logType, desc, remark, spare) // 查询多条数据 rows, err3 := db.Query("SELECT admin_username,log_time,log_ip,log_type,log_desc" + " FROM admin_log WHERE id=? OR id=?", 2017, 2019) errDeal("查询多条数据", err3) // 对多条数据进行遍历 for rows.Next() { err4 := rows.Scan(&username, &time, &ip, &logType, &desc) errDeal("遍历多条数据", err4) fmt.Printf("username=%s,time=%s,ip=%s,logType=%s,desc=%s\n", username, time, ip, logType, desc) } // 如果查询中不指定具体字段，使用* rows, err33 := db.Query("SELECT *" + " FROM admin_log WHERE id>?", 2017) errDeal("查询多条数据", err33) // 查询所有字段名，返回string切片 columes, err333 := rows.Columns() errDeal("rows.Columns()方法调用", err333) fmt.Printf("%T----%v\n", columes, columes) var scanColumes = make([]interface{}, len(columes)) var values = make([]interface{}, len(columes)) for index, _ := range scanColumes { scanColumes[index] = &values[index] } for rows.Next() { err4 := rows.Scan(scanColumes...) errDeal("遍历多条数据", err4) for i, val := range values { if strings.EqualFold(checkType(val), "[]uint8") { fmt.Printf("%s(%T)==%s\t", columes[i], val, val) } else { fmt.Printf("%s(%T)==%v\t", columes[i], val, val) } } fmt.Println() } // ==================================================================================================事务 // 开启事务，tx是从连接池中取出一个连接，在关闭之前都是使用这个连接，提交事务和回滚事务都是操作tx tx, err5 := db.Begin() errDeal("开启事务", err5) _, err6 := tx.Exec("UPDATE admin_log SET log_desc=? WHERE id=?", "测试事务222", 2019) //if err6 != nil { if err6 == nil { tx.Rollback() // 回滚 } tx.Commit() // 提交 // 批量数据插入 tx, err7 := db.Begin() errDeal("数据批量插入，开启事务", err7) insertValues := [][]interface{}{{"admin", "127.0.0.1", "登录", "登录成功"},{"admin", "127.0.0.1", "删除", "删除数据"},{"admin", "127.0.0.1", "退出", "退出系统"}} stmt, err8 := tx.Prepare("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc) VALUES(?,now(),?,?,?)") errDeal("数据批量插入，预处理", err8) defer stmt.Close() // 通过循环将每条SQL的参数写到目标表缓冲区。 for _, val := range insertValues { _, err := stmt.Exec(val...) if err != nil { fmt.Printf("出现错误回滚，错误信息：%v", err) tx.Rollback() } } tx.Commit() // 使用sqlx批量数据插入 xdb, err9 := sqlx.Open("mysql", "root:root@tcp(127.0.0.1:3306)/betting?charset=utf8") errDeal("sqlx连接数据库", err9) defer xdb.close() txx, err10 := xdb.Beginx() errDeal("sqlx开启事务", err10) insertValuesx := [][]interface{}{{"admin", "127.0.0.1", "登录", "登录成功X"},{"admin", "127.0.0.1", "删除", "删除数据X"},{"admin", "127.0.0.1", "退出", "退出系统X"}} stmtx, err11 := txx.Preparex("INSERT INTO admin_log(admin_username,log_time,log_ip,log_type,log_desc) VALUES(?,now(),?,?,?)") errDeal("数据批量插入，预处理", err11) defer stmtx.Close() // 通过循环将每条SQL的参数写到目标表缓冲区。 for _, val := range insertValuesx { _, err := stmtx.Exec(val...) if err != nil { fmt.Printf("sqlx出现错误回滚，错误信息：%v", err) txx.Rollback() } } txx.Commit()}func errDeal(info string, err error) { if err != nil { panic(fmt.Sprintf("%s，错误信息：%v", info, err)) }}func checkType(val interface{}) string { switch val.(type) { case []uint8 : return "[]uint8" } return ""}
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