auto connection problem when using go 1.2

[zx9597446]

hello, I found a bug when using this driver, and I'm not sure this bug is from driver or database/sql.

go version: 1.2
driver version: 1.1 (9a7aa3606b82e2081a13a008ada88dfdb96c20fd)
mysql version: mysql ver 15.1 distrib 10.0.4 - mariadb
client os: win7

bug describe in brief:

1. Stmt.QueryRow() failed return results util next call. here are steps:
   a). prepare a Stmt with "select" query
   b). kill database connection.
   c). call Stmt.QueryRow.Scan() will fail util next call
   outputs:

[MySQL] 2014/01/09 10:27:35 packets.go:30: EOF
[MySQL] 2014/01/09 10:27:35 statement.go:24: Invalid Connection
[MySQL] 2014/01/09 10:27:35 statement.go:24: Invalid Connection

1. Stmt.Exec failed return results, and never reconnect to database, here are steps:
   a). prepare a Stmt with "insert" query.
   b). kill database connection.
   c). call Stmt.Exec() will fail and never reconnect to database.
   outputs:

[MySQL] 2014/01/09 10:38:25 packets.go:30: EOF   <----first call Stmt.Exec()
2014/01/09 10:38:25 [::1] - �[32;1m GET /test2�[0m - 1ms
[MySQL] 2014/01/09 10:38:32 statement.go:39: Invalid Connection   <---- next call to Stmt.Exec() 
2014/01/09 10:38:32 [::1] - �[32;1m GET /test2�[0m - 1.0001ms

my test source code:

package main

import (
    "database/sql"
    "fmt"
    "math/rand"
    "time"
)
import "github.com/hoisie/web"
import _ "github.com/go-sql-driver/mysql"

import "runtime"

const sql1 = "select username from user_table where uid=?"
const sqlInsertUser = "insert into user_table set username = ?, password = ?, source=?"

var db *sql.DB
var db2 *sql.DB
var stmt *sql.Stmt
var stmt2 *sql.Stmt

func panicIf(err error) {
    if err != nil {
        panic(err)
    }
}

func init() {
    var err error
    db, err = sql.Open("mysql", "root:root@tcp(192.168.0.32:3306)/userdb")
    panicIf(err)
    //db2, err = sql.Open("mysql", "root:root@tcp(192.168.0.32:3306)/userdb")
    stmt, err = db.Prepare(sql1)
    panicIf(err)
    stmt2, err = db.Prepare(sqlInsertUser)
    panicIf(err)
    runtime.GOMAXPROCS(runtime.NumCPU())
    rand.Seed(time.Now().UnixNano())
}

func test() string {
    var username string
    stmt.QueryRow(14740).Scan(&username)

    return username
}

func test2() string {
    iu := rand.Uint32()
    ip := rand.Uint32()
    su := fmt.Sprintf("%d", iu)
    sp := fmt.Sprintf("%d", ip)
    _, err := stmt2.Exec(su, sp, "")
    if err != nil {
        return err.Error()
    }
    return "Ok"
}

func main() {
    web.Get("/", test)
    web.Get("/test2", test2)
    web.Run("0.0.0.0:80")
}

[julienschmidt]

Looks a lot like http://golang.org/issue/5718
This should be fixed in Go tip: https://code.google.com/p/go/source/detail?r=3662d56e2402

[zx9597446]

to solve the problem, should I build go from source myself?
any other ways?

[arnehormann]

Yes you should and no, there's no way not involving waiting unless you find a packaged version of tip for your OS.

[julienschmidt]

You could just update the database/sql package (just replace the source files in $GOROOT/src/pkg/database/sql). Don't forget to delete $GOROOT/pkg/database/sql, otherwise the cached package version is used.

[zx9597446]

ok, update to tip solved the problem