Dollar ($) Sign in Password String Causes Database Connection Issues

In a recent encounter, a PHP application experienced difficulties establishing a connection to a MySQL database. Despite using the correct credentials, the database remained inaccessible.

Investigation revealed that the password contained a dollar ($) sign:

$_DB["password"] = "mypas$word";

This caused the password to be truncated to "mypas" when sent to the database, leading to the connection failure.

Solution

The issue was resolved by escaping the dollar sign with a backslash:

$_DB["password"] = "mypas\$word";

This allowed the password to be sent to the database correctly.

Best Practice

To avoid such issues, it's recommended to use single-quoted strings for database passwords:

$_DB['password'] = 'mypas$word';

Single-quoted strings are not processed and are interpreted as-is. This approach is faster and less prone to errors.