test.php

<?php
    
    $sql = "SELECT o.name AS objects_name, o.desc AS objects_desc FROM objects AS o WHERE MATCH(o.name, o.desc) AGAINST ('tak')
    UNION ALL(SELECT c.name AS communes_about, c.about AS communes_about WHERE MATCH (c.name, c.about) AGAINST ('tak'))
    UNION ALL(SELECT d.name AS district_name, d.about AS district_about FROM district AS d WHERE MATCH (d.name, d.about) AGAINST ('tak'))";