Call to undefined function mysql_ Connect() solution summary

Use the phpinfo() function in your PHP code to see PHP basics
Mysql_connect () has been deprecated since PHP5.0, and is deprecated in PHP7.0. Mysqli_connect () is used instead if PHP is 7.0 or higher
Method 2:
Missing MySQL module caused by PHP installation
Mysql> install mysql from CentOs
yum install php-mysql -y
If installed, report the following warning
Headers and client library minor version mismatch. Headers:
This is due to the higher version of MySQL, the lower version of the MySQL Client API
You can uninstall php-mysql first
yum remove php-mysql -y
yum install php-mysqlnd -y
Finally, restart Apache
systemctl restart httpd
Ubuntu install MySQL module:
Apt to get the install php5 – mysql
Sudo DPKG — reconfigure php5 – mysql
sudo /etc/init.d/mysql restart
sudo /etc/init.d/apache2 restart
If the first two methods fail, try opening the MySQL module extension in the php.ini configuration file
Php.ini = php.ini; Extension =” related MySQL module “; To get rid of
Then make sure that the dir of extension points to the directory where the extension resides
Windows is usually under Ext and CentOS is under /usr/lib64/php.modules
The above information can be found in the PHPINFO printed information
However, when I encountered this problem, I just needed to install the PHP-MySQL module, and I didn’t need to modify php.ini
My environment is Centos7 and PHP version is PHP5.4

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