TYPO3 extbase get SQL statement from query

MyRepository.php

<?php
class MyRepository extends Repository
{
    function findSome() {
        $query        = $this->createQuery();
        $query->matching(
            // ...
        );
        $queryParser = $this->objectManager->get(\TYPO3\CMS\Extbase\Persistence\Generic\Storage\Typo3DbQueryParser::class);
        \TYPO3\CMS\Extbase\Utility\DebuggerUtility::var_dump($queryParser->convertQueryToDoctrineQueryBuilder($query)->getSQL());
    }
}

Today you would use GeneralUtility to get the Typo3DbQueryParser:

$queryParser = GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\Persistence\Generic\Storage\Typo3DbQueryParser::class);

Besides getSQL() the method getParameters() is very helpful. See official documentation.