Question

Are there any performance concerns of note when using MySQL’s CONCAT() function in a select query? Is it faster/slower/negligible to do a simple select, and format strings for a view using PHP after the result set from the database is returned? Or is a more complicated SQL query with multiple calls to CONCAT() that returns a string already formatted for the view a better approach?

ie is this:

select CONCAT(lastname, ', ', firstname) from people;

Faster/Slower/No difference from this:

<?php
    $query = 'Select lastname, firstname from people';
    ...

    $name = $data['lastname'] . ', ' . $data['firstname']; //OR
    $name = sprintf("%s, %s", $data['lastname'], $data['firstname']);
?>

Answer 1

You’re better off in almost all cases by doing filtering and data massaging with the SQL engine versus on the web server.