一尘不染

是否存在Go Mysql驱动程序,该驱动程序在单个字符串中支持多个语句?

go

我正在尝试找到可以与Go一起使用的MySql驱动程序,该驱动程序支持在一个调用中发出多个SQL语句。例如,我可能希望使用以下SQL创建数据库:

DROP SCHEMA IF EXISTS foo;
CREATE SCHEMA IF NOT EXISTS foo;

在PHP之类的语言中,您可以将两个SQL语句放在一个字符串中,然后一次性执行,如下所示:

$db = new PDO(...);
$db->query("DROP SCHEMA IF EXISTS foo; CREATE SCHEMA IF NOT EXISTS foo;");

我需要这个的原因是因为我有SQL转储(来自mysqldump),我想以编程方式应用于各种数据库。

我在Go中寻找相同的功能,但似乎所有不同的驱动程序都不支持它,坦率地说,这让我感到震惊。

Go-MySQL-Driver
https://github.com/go-sql-driver/mysql
这似乎是Go中最常用的驱动程序。

package main

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

func main() {

    db, err := sql.Open("mysql", "user:password@(127.0.0.1:3306)/")
    if err != nil {
        log.Println(err)
    }

    sql := "DROP SCHEMA IF EXISTS foo; CREATE SCHEMA IF NOT EXISTS foo;"
    _, err = db.Exec(sql)
    if err != nil {
        log.Println(err)
    }

    db.Close()
}

输出:

2015/02/16 18:58:08 Error 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CREATE SCHEMA IF NOT EXISTS foo' at line 1

MyMySQL
https://github.com/ziutek/mymysql
这是另一个流行的驱动程序。

package main

import "database/sql"
import "log"
import _ "github.com/ziutek/mymysql/godrv"

func main() {

    db, err := sql.Open("mymysql", "database/user/password")
    if err != nil {
        log.Println(err)
    }

    sql := "DROP SCHEMA IF EXISTS foo; CREATE SCHEMA IF NOT EXISTS foo;"
    _, err = db.Exec(sql)
    if err != nil {
        log.Println(err)
    }

    sql = "USE DATABASE foo;"
    _, err = db.Exec(sql) // <-- error
    if err != nil {
        log.Println(err)
    }

    db.Close()
}

输出:

2015/02/16 18:58:08 packet sequence error

有谁知道与Go兼容的MySql驱动程序,可以在一个这样的字符串中处理多个语句?


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2020-07-02

共1个答案

一尘不染

https://github.com/ziutek/mymysql

可以做到。尽管您必须使用其接口与已定义的接口。go官方接口无法处理它,或有多个返回值。

package main

import (
    "flag"
    "fmt"

    "github.com/ziutek/mymysql/autorc"
    "github.com/ziutek/mymysql/mysql"
    _ "github.com/ziutek/mymysql/thrsafe"
)

type ScanFun func(int, []mysql.Row, mysql.Result) error

func RunSQL(hostport, user, pass, db, cmd string, scan ScanFun) error {
    conn := autorc.New("tcp", "", hostport, user, pass, db)

    err := conn.Reconnect()
    if err != nil {
        return err
    }

    res, err := conn.Raw.Start(cmd)
    if err != nil {
        return err
    }

    rows, err := res.GetRows()
    if err != nil {
        return err
    }

    RScount := 0
    scanErr := error(nil)

    for {
        if scanErr == nil {
            func() {
                defer func() {
                    if x := recover(); x != nil {
                        scanErr = fmt.Errorf("%v", x)
                    }
                }()
                scanErr = scan(RScount, rows, res)
            }()
        }

        if res.MoreResults() {
            res, err = res.NextResult()
            if err != nil {
                return err
            }
            rows, err = res.GetRows()
            if err != nil {
                return err
            }
        } else {
            break
        }

        RScount++
    }
    return scanErr
}

func main() {
    host := flag.String("host", "localhost:3306", "define the host where the db is")
    user := flag.String("user", "root", "define the user to connect as")
    pass := flag.String("pass", "", "define the pass to use")
    db := flag.String("db", "information_schema", "what db to default to")

    sql := flag.String("sql", "select count(*) from columns; select * from columns limit 1;", "Query to run")

    flag.Parse()

    scan := func(rcount int, rows []mysql.Row, res mysql.Result) error {
        if res.StatusOnly() {
            return nil
        }

        for idx, row := range rows {
            fmt.Print(rcount, "-", idx, ") ")
            for i, _ := range row {
                fmt.Print(row.Str(i))
                fmt.Print(" ")
            }
            fmt.Println("")
        }
        return nil
    }

    fmt.Println("Host - ", *host)
    fmt.Println("Db   - ", *db)
    fmt.Println("User - ", *user)

    if err := RunSQL(*host, *user, *pass, *db, *sql, scan); err != nil {
        fmt.Println(err)
    }
}
2020-07-02