Javaer to go MySQL operation

This is a creation in Article, where the information may have evolved or changed.

After degrees Niang, found that more commonly used Golang MySQL driver package has two mymysql and Go-sql-driver/mysql. Personally feel that the name Mymysql is not elegant. So I chose the go-sql-driver/mysql.

1, the installation of Go-sql-driver/mysql

Because Go-sql-driver/mysql belongs to a third-party package, we need to get to this package first.

Add the installation package to our $gopath through the system's Shell tool (command line).

go get github.com/go-sql-driver/mysql

Note here: Use the above command not only to configure the Golang environment, but also to configure the Git bin directory in the PATH environment variable.

2. Operation MySQL

• Guide Package

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

Because we use the process, not directly to the go-sql-driver/mysql, but through the interface in the Database/sql to use the driver, this is the same as the idea of Java. So when we import the Go-sql-driver/mysql package, we use underscores as placeholders to tell Golang that the contents of this package will not be used directly.

Note:

If you import a package without using it, you will throw an error when building the program, such as imported and not Used:os, which follows the motto of Go: "No unnecessary code!" “。

The declaration of a variable, too, throws an error if you declare a variable without using the variable.

The presence of placeholders solves the problem of importing the package without explicitly using the package.

• Establish a connection

db, err := sql.Open("mysql""用户名:密码@/数据库名?charset=utf8")

The open function returns two values, but if we need only the DB value, regardless of the error, you can use a placeholder:

db, _:= sql.Open("mysql""用户名:密码@/数据库名?charset=utf8")

• Exec

_, err := db.Exec(sql)

The EXEC function can execute a SQL that does not return, such as delete, UPDATE, insert operations.

• Prepare
  Preprocessing a broken-down method to process SQL
  Such as:

Increase:

err := db.Prepare(`INSERT user (user_name,user_age,user_sex) values (?,?,?)`)checkErr(errerr := stmt.Exec("tony"201)checkErr(errerr := res.LastInsertId()checkErr(err)

Modify:

errSET user_age=?,user_sex=? WHERE user_id=?`)checkErr(errerr := stmt.Exec(2121)checkErr(errerr := res.RowsAffected()checkErr(err)

Delete:

err := db.Prepare(`DELETE FROM user WHERE user_id=?`)checkErr(errerr := stmt.Exec(1)checkErr(errerr := res.RowsAffected()checkErr(err)

• Query

The query returns more than one record.

    err := db.Query("select id,nickname from user")    iferr != nil {        fmt.Println(err.Error())    }    defer rows.Close()    for rows.Next() {        int        string        rows.Scan(&id, &nickname)        fmt.Println(nickname)    }    db.Close()

• Queryrow
  The query returns a record.

 row: = Open ().    Queryrow ( "select Id,nickname from user where id=129986" ) var  ID int  var  nickname string  row. Scan (&id, &nickname)