PHP-mysql_num_rows()期望参数1为资源,字符串在

我已经阅读了许多其他有关此确切问题的线索,但由于某种原因我无法解决我的问题.确实需要一些帮助.

if (!$username||!$password||!$email)
    echo "Please fill out all fields"; 
 else
 {
    //encrypt password
    $password = md5($password);

    //check if username already taken
    $check = MysqL_query("SELECT * FROM Test WHERE username = '$username'");
    if (MysqL_num_rows($check)>=1)
       echo "Username already taken";

    else

它说

Warning: MysqL_num_rows() expects parameter 1 to be resource, string
given in /Users…..

if(MysqL_num_rows($check)> = 1)这行..但是当我在PHPmyadmin中运行它时,它会向我返回结果.

请帮忙

解决方法:

更改：

$check = MysqL_query("SELECT * FROM Test WHERE username = '$username'");

至

$check = MysqL_query("SELECT * FROM Test WHERE username = '$username'") or die(MysqL_error());

您将看到查询中发生的任何潜在错误.

另外,我强烈建议使用PDO或MysqLi而不是MysqL函数,因为它们已被弃用,并将在以后的PHP版本中删除.