golang 如何将sql.open 写成全局？

修改一下

import (
    _ "code.google.com/p/go-mysql-driver/mysql"
    "database/sql"
    "fmt"
    "time"
)   
func GetConn() *sql.DB {
    db, err := sql.Open("mysql", "root:root@/blog?charset=utf8")
    checkErr(err)
    return db
}
func main() {
    time := time.Now().Unix()
    stmt, err :=  GetConn().Prepare("insert blog_user set username=?, password=?, created=?")
    checkErr(err)
    res, err := stmt.Exec("anaru", "test", time)
    checkErr(err)
    id, err := res.LastInsertId()
    checkErr(err)
    fmt.Println(id)