mysql_connect错误

Question

In the following code I see echo1 statement, after which I do not see anything printed on the UI.The username and password is correct. But PHP doesn't seem to connect to MySQL. Don't even see the die statement what am I doing wrong. After mysql_connect is encountered the rest of the code doesn't work:

<?php    
echo "echo1==========";
$con = mysql_connect("localhost","root", "xxxx123") or die("Error connecting to database");
echo "+++++++++ echo2";
echo $con;
mysql_close($con);
  ?>          

Answer 1

You should be mising an error. Add :

ini_set('display_errors', 1);
error_reporting(E_ALL);

at the beggining of your script

Answer 2

If you use your code just like this then it's vulnerable for SQL Injection. I would strongly recommend using mysql_real_escape_string as you insert data into your database to prevent SQL injections , as a quick solution or better use PDO or MySQLi .

If you are going to use mysql_* then I'd recommend reading the PHP manual chapter on the mysql_* functions, where they point out, that this extension is not recommended for writing new code. Instead, they say, you should use either the MySQLi or PDO_MySQL extension.

I also checked mysql_connect and found a weird regularity which is - if you use " on mysql_connect arguments, then it fails to connect and in my case, when I was testing it, it happened just described way, so, please try this instead:

$con = mysql_connect('localhost','username','password');

Replace " to ' as it's shown in the PHP Manual examples and it might work!

EDITED

For those who downvote - TRY first! I tested it on my server with " and it gave me an error: Warning: mysql_connect(): Access denied for user . I use PHP version 5.4.6!

Login to your server with SSH and run php --modules - if you don't see mysql in the list - then it's the reason of your fatal error.

Answer 3

No output means a fatal error. The only possible fatal error is "undefined function mysql_connect (unless something's really messed up somewhere). This means the mysql library is not installed, or it might just not be enabled in the php.ini file.

Check said file, and while you're at it turn error_reporting on.

Answer 4

问题是没有安装ph5-mysql驱动程序。安装并使其运行..现在mysql_connect（）函数可以运行了。.感谢所有帮助

Answer 5

For Tomcat 7, the default dir for php.ini is actually C:\\windows. So modified (enabling modules, extensions etc.) php.ini should be copied to C:\\windows. Then run phpinfo();. It should work fine even on Tomcat 7 along side PHP 5.x. I had this problem and struggled a lot when I wanted the mysql statements to work.

Even after following all instructions from answers in [779246] ( Run a php app using tomcat? ), mysql statements didn't work (Tomcat 7, PHP 5.2.16, PECL 5.2.5, MySql 5.6 on Windows 7). So I started looking into "phpinfo();" output carefully and used solution as mentioned in earlier paragraph. Please be sure to enable mysql dll extension and also PDO extensions in php.ini if you would like to use PDO (which is future of plain mysql_* methods in PHP).