golang中连接mysql

---

笔者使用的go的mysql驱动是go-sql-driver, 这个在github上star的比较多，支持database/sql，维护的比较好,

• 代码地址:
  https://github.com/go-sql-driver/mysql
• 文档地址
  https://godoc.org/github.com/go-sql-driver/mysql
• 代码示例
  https://github.com/go-sql-driver/mysql/wiki/Examples

1. 驱动安装

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

2. 创建一个测试表

CREATE TABLE `test_userinfo` (
  `user_id` bigint(20) NOT NULL,
  `user_name` varchar(128) DEFAULT NULL,
  `user_image` int(11) DEFAULT NULL,
  `user_score` double DEFAULT NULL,
  `last_modify_time` datetime DEFAULT NULL,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

3. 测试代码

连接的uri格式
user@unix(/path/to/socket)/dbname?charset=utf8
user:password@tcp(localhost:5555)/dbname?charset=utf8
user:password@/dbname
user:password@tcp([de:ad:be:ef::ca:fe]:80)/dbname
第二种是最常用的

// mysql_test project main.go
package main

import (
    "database/sql"
    "fmt"

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

func err_handler(err error) {
    fmt.Printf("err_handler, error:%s\n", err.Error())
    panic(err.Error())
}

func test_delete_tb() {
    fmt.Println("test delete db")

    var sql_uri = "root:123456@/test_db?charset=utf8"

    db, err := sql.Open("mysql", sql_uri)

    if err != nil {
        err_handler(err)
    }

    defer db.Close()

    var delete_sql string = "delete from test_userinfo"
    _, err = db.Exec(delete_sql)
    if err != nil {
        fmt.Printf("try do sql[%s] error[%s]\n", delete_sql)
        err_handler(err)
    }
}

func test_query() {
    fmt.Println("test_query!")

    var sql_uri = "root:123456@/test_db?charset=utf8"

    db, err := sql.Open("mysql", sql_uri)

    if err != nil {
        err_handler(err)
    }

    defer db.Close()

    var query_sql string = "select * from test_userinfo"
    rows, err := db.Query(query_sql)
    if err != nil {
        fmt.Printf("try do query_sql[%s] error[%s]\n", query_sql, err.Error())
        err_handler(err)
    }

    // get columns
    columns, err := rows.Columns()
    if err != nil {
        fmt.Printf("try get result set columns error[%s]\n", err.Error())
        err_handler(err)
    }

    for i, colname := range columns {
        fmt.Printf("col %d, name: %s\n", i, colname)
    }

    values := make([]sql.RawBytes, len(columns))

    // scan the result set
    scan_args := make([]interface{}, len(values))
    for i := range values {
        scan_args[i] = &values[i]
    }

    // fetch rows
    for rows.Next() {
        err = rows.Scan(scan_args...)
        if err != nil {
            fmt.Printf("try scan rows error[%s].\n", err.Error())
            err_handler(err)
        }

        var value string
        for i, col := range values {
            if col != nil {
                value = string(col)
            } else {
                value = "NULL"
            }

            fmt.Printf("col %d = %s\n", i, value)
        }

        fmt.Printf("---------------------------------\n\n")
    }

    if err = rows.Err(); err != nil {
        fmt.Printf("rows.err [%s]\n", err.Error())
        err_handler(err)
    }
}

func test_prepare_insert() {
    fmt.Println("test_prepare_insert!")

    var sql_uri = "root:123456@/test_db?charset=utf8"

    db, err := sql.Open("mysql", sql_uri)

    if err != nil {
        err_handler(err)
    }

    defer db.Close()

    var insert_prepare_sql string = "insert into test_userinfo(user_id, user_name, user_image, user_score, last_modify_time) values(?, ?, ?, ?, now())"
    stmt_in, err := db.Prepare(insert_prepare_sql)
    if err != nil {
        fmt.Printf("try prepare stmt[%s] error[%s]", insert_prepare_sql, err.Error())
        err_handler(err)
    }
    defer stmt_in.Close()

    var base_user_id int = 1000
    for i := 0; i < 10; i++ {
        base_user_id++
        user_name := fmt.Sprintf("user_%d", base_user_id)

        _, err = stmt_in.Exec(base_user_id, user_name, i, 100+i)
        if err != nil {
            fmt.Printf("try do prepare exe error[%s]", err.Error())
            err_handler(err)
        }
    }

    var query_prepare_sql string = "select user_name, user_image from test_userinfo where user_id = ?"
    stmt_out, err := db.Prepare(query_prepare_sql)
    if err != nil {
        fmt.Printf("try prepare stmt[%s] error[%s]\n", query_prepare_sql, err.Error())
        err_handler(err)
    }
    defer stmt_out.Close()

    base_user_id = 1000
    var user_name string
    var user_image int
    for i := 0; i < 12; i++ {
        base_user_id++

        err = stmt_out.QueryRow(base_user_id).Scan(&user_name, &user_image)
        if err != nil {
            fmt.Printf("try do query row user_id[%d] error[%s]\n", base_user_id, err.Error())
            // err_handler(err)
        }

        fmt.Printf("res, user_id[%d] =>  user_name[%s] user_image[%d]\n", base_user_id, user_name, user_image)
    }

    fmt.Printf("************************************************\n\n")
}

func main() {
    test_delete_tb()
    test_prepare_insert()
    test_query()
}