/**
* Appends query parts from registered mappers
*
* @param \Krystal\Db\Sql\QueryBuilderInterface $db Query builder
* @return void
*/
private function appendFromMappers(QueryBuilderInterface $qb)
{
// Amount of registered mappers we have
$amount = count($this->mappers);
// Iteration counter
$i = 0;
foreach ($this->mappers as $mapper) {
$qb->openBracket();
$mapper->appendQuery($qb, self::PARAM_QUERY_PLACEHOLDER);
$qb->closeBracket();
++$i;
// Comparing iteration against number of mappers, tells whether this iteration is last
$last = $i == $amount;
// If we have more that one mapper, then we need to union results
// And also, we should never append UNION in last iteration
if ($amount > 1 && !$last) {
$qb->union();
}
}
}
