MySQL Register ERROR

Getting Help
1

Hi,

My Code:


package main

import (
	"database/sql"
	"fmt"
	"log"
	"net/http"


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

var db *sql.DB

func init() {
	sql.Register("mysql", &mysql.MySQLDriver{})
}

func main() {

	db, err := sql.Open("mysql", "user:password@tcp(xx.xxx.xxx.xxx)/hallo?charset=utf8")
	if err != nil {
		log.Fatal(err)
	}

	var name string
	err = db.QueryRow("select name from users where id = ?", 1).Scan(&name)
	if err != nil {
		log.Fatal(err)
	}
}

error output:

panic: sql: Register called twice for driver mysql

goroutine 1 [running]:
panic(0x826de0, 0xc082005540)
	c:/go/src/runtime/panic.go:481 +0x3f4
database/sql.Register(0x994630, 0x5, 0x1224698, 0xc45ef0)
	c:/go/src/database/sql/sql.go:45 +0x188
....

Why twice?

2

Importing the mysql library registers it. You’re seeing this error because you’re registering it again. The recommended solution is to import it with a preceding underscore:

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

This registers mysql but prevents “unused import” errors.

1 Like
3

Thx… :slight_smile:

4

No problem. I find the whole SQL driver paradigm (the “register-by-import” bit) to be rather unintuitive; fortunately it’s one of those things you run into it once or twice and then learn.

5

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