---
title: "Breaking: #77379 - Doctrine: Typo3DbQueryParser"
manual: "TYPO3 Core Changelog"
version: "main"
permalink: "https://docs.typo3.org/permalink/changelog:breaking-77379"
source: "Changelog/8.4/Breaking-77379-DoctrineTypo3DbQueryParser.rst"
typo3-version: "8.4"
typo3-major: 8
type: "breaking"
issue: 77379
forge: "https://forge.typo3.org/issues/77379"
tags: ["PHP-API", "Database"]
rendered: "2026-09-20T18:31:11+00:00"
---

# Breaking: #77379 - Doctrine: Typo3DbQueryParser {#breaking-77379}

See [forge#77379](https://forge.typo3.org/issues/77379)

## Description {#description}

While migrating the database endpoint for the persistence functionality of Extbase to Doctrine DBAL, the `Typo3DbQueryParser` class
has been completely rewritten to work on a `QueryBuilder` object instead of plain arrays and strings. The PHP method
`Typo3DbQueryParser->parseQuery()` has been removed, instead the new equivalent
`Typo3DbQueryParser->convertQueryToDoctrineQueryBuilder()` has been introduced.

Additionally, the PHP method `Typo3DBBackend->injectQueryParser()` has been removed, as the `Typo3DbQueryParser` class is not a
singleton instance anymore but always rebuilt when needed.

## Impact {#impact}

Calling one of the methods above will result in a fatal PHP error.

## Affected Installations {#affected-installations}

TYPO3 instances with custom Extbase database backend and parsing functionality.

## Migration {#migration}

Switch to Doctrine DBAL and `Typo3DbQueryParser->convertQueryToDoctrineQueryBuilder()` which results in the same behaviour.