PHP Warning: PHP Startup: Unable to load dynamic library 'pdo_mysql.so'

Question

I ran the command:

php -v

Output:

PHP Warning:  PHP Startup: Unable to load dynamic library 'pdo_mysql.so' (tried: /usr/lib/php/20170718/pdo_mysql.so (/usr/lib/php/20170718/pdo_mysql.so: undefined symbol: mysqlnd_allocator), /usr/lib/php/20170718/pdo_mysql.so.so (/usr/lib/php/20170718/pdo_mysql.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0

I ran this command:

php -m

Output:

PHP Warning:  PHP Startup: Unable to load dynamic library 'pdo_mysql.so' (tried: /usr/lib/php/20170718/pdo_mysql.so (/usr/lib/php/20170718/pdo_mysql.so: undefined symbol: mysqlnd_allocator), /usr/lib/php/20170718/pdo_mysql.so.so (/usr/lib/php/20170718/pdo_mysql.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
    [PHP Modules]
    bz2
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    Zend OPcache
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    [Zend Modules]
    Zend OPcache

The php.ini file contains this line:

extension=pdo_mysql

Ran this command:

sudo apt-get install -y php-pdo-mysql

Nothing is installed, because it is already installed.

Ran this command:

php -i

Output shows:

PDO

PDO support => enabled
PDO drivers =>

Not sure why this is or what to do. Any suggestions?

Answer 1

I solved the problem this way:

sudo apt-get --purge remove php-common

sudo apt-get install php-common php-mysql php-cli

Now there is no error and php -m shows it has everything:

Answer 2

You are probably using php7.2, so you should edit the php.ini file (/etc/php/7.2/cli/php.ini).

And probably extension=pdo_mysql on line 906 is uncommented. Comment this line by adding ; at the beginning of the line.

After saving and closing php.ini the error should disappear, however, to ensure that the changes take effect, restart the php service:

$ sudo systemctl restart php7.2-fpm

Answer 3

Make sure that the location of pdo_mysql.so file is the same of the PHP extension_dir:

# php -i|grep extension_dir

# find / -name pdo_mysql.so

By doing this, and adding the absolute path on the php.ini like this:

extension=/usr/lib/php/20190902/pdo_mysql

this will work.