go - 为什么 defer stmnt.Close() 似乎会阻止我的 http.Redirect？

Question

为什么我的 defer stmnt.Close() 似乎阻止了我的 http.Redirect 重定向它只是卡在网站上无限尝试加载。

但是如果我删除 defer stmnt.Close() 它重定向就好了吗？

    err = db.QueryRow("SELECT steamid FROM accounts WHERE steamid = ?", ids).Scan(&steamid)
    if err != nil {
        common.WriteLog(err.Error(), r)
        http.Error(w, "Failed to connect to database. Try again in a bit.", 500)
    }

    switch {
    case len(profile.Response.Players) == 0:
        common.WriteLog("Failed to look you up in the steam database. Try again in a bit.", r)
        http.Error(w, "Failed to look you up in the steam database. Try again in a bit.", 500)
    case err == sql.ErrNoRows:
        stmnt, err := db.Query("INSERT INTO accounts SET steamid=?", ids)
        if err != nil {
            common.WriteLog(err.Error(), r)
            http.Error(w, "Failed to insert your account to the database. Try again in a bit.", 500)
        }
        defer stmnt.Close() // <<<<< The suspect
        // Insert Account

        http.Redirect(w, r, "/", 303)
    case err != nil:
        common.WriteLog(err.Error(), r)
        http.Error(w, "Failed to insert your account to the database. Try again in a bit.", 500)

    default:
        // Login User

        http.Redirect(w, r, "/", 303)

    }

Answer 1

使用 db.Exec 而不是 db.Query。

Exec executes a query without returning any rows.

对比

Query executes a query that returns rows

至于为什么，我猜是mysql Rows.Close 正在等待数据on the connection :

func (rows *mysqlRows) Close() error {
    mc := rows.mc
    if mc == nil {
        return nil
    }
    if mc.netConn == nil {
        return ErrInvalidConn
    }

    // Remove unread packets from stream
    err := mc.readUntilEOF()
    rows.mc = nil
    return err
}

这永远不会发生。

参见 this例如。