Fatal error: Call to undefined function sqlsrv_connect()

Question

When you install third-party extensions you need to make sure that all the compilation parameters match:

Common glitches includes:

Editing the wrong php.ini file (that’s typical with bundles); the right path is shown in phpinfo().
Forgetting to restart Apache.
Not being able to see the startup errors; those should show up in Apache logs, but you can also use the command line to diagnose it, e.g.:
```
php -d display_startup_errors=1 -d error_reporting=-1 -d display_errors -c "C:\Path\To\php.ini" -m
```

If everything’s right you should see sqlsrv in the command output and/or phpinfo() (depending on what SAPI you’re configuring):

[PHP Modules]
bcmath
calendar
Core
[…]
SPL
sqlsrv
standard
[…]

phpinfo()