Catch database error message

Code:

A PHP Error was encountered
Severity: Notice
Message: Array to string conversion
Filename: controllers/Test.php
Line Number: 95
Backtrace:
File: C:\xampp\htdocs\test\application\controllers\test.php
Line: 95
Function: _error_handler

File: C:\xampp\htdocs\test\index.php
Line: 296
Function: require_once

Code:

Configuration doesn't saved
Array
0
0

Still get error message Array to string conversion