我想用 PHP 代码检查数据库中是否有给定电子邮件地址的任何记录,但是当我在数据库中有该电子邮件地址时,它说“不存在”!这段代码有什么问题?
$con=mysql_connect("localhost","gvf_lingo","btrbghtre544","vtrbt_lingo");
$result = mysql_query("SELECT user_email FROM rating WHERE user_email='testuser@gmail.com'");
$num_rows = mysql_num_rows($result);
if ($num_rows > 0) {
echo "exist";
}else{
echo "does not exist";
}
最佳答案
您提供的连接字符串不正确。应该是什么,
$con = mysql_connect("localhost","gvf_lingo","btrbghtre544");
mysql_select_db("vtrbt_lingo",$con);
已更新
正如评论中提到的 PleaseStand mysqli 接受数据库名称作为第四个参数。
$mysqli = new mysqli('localhost', 'my_user', 'my_password', 'my_db');
注意: Please, don't use mysql_*
functions in new code .它们不再维护 and are officially deprecated .查看red box ?了解 prepared statements相反,并使用 PDO , 或 MySQLi - this article将帮助您决定选择哪个。如果选择 PDO,here is a good tutorial .
关于php - 检查记录是否存在于php中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16292984/