rename database field in upgrade wizard of an extension in TYPO3 11

I have an upgrade wizard (TYPO3 11) which changes the data of a table.
This is done with the querybuilder:

$queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
					->getQueryBuilderForTable('tt_content');

$queryBuilder
	->update('tt_content')
	->set('CType', 'newCType')
	->where($queryBuilder
				->expr()
				->eq('CType',$queryBuilder->createNamedParameter('oldCType')))
	->execute();

But I also need to rename a field in a table:

ALTER TABLE tt_content RENAME COLUMN tx_myext_old_field TO tx_myext_new_field;

I can't find any documentation or example of doing this with the querybuilder.

The normal way woult be to provide a ext_tables.sql in your extension. This is read by TYPO3 to build a virtual "database scheme" how it should look.

The database schema analyser will than provide the information, and database alteration are suggested.

You could add a database must be up to date constraint to your upgrade wizard, that way it is ensured that the field is changed.

DTL is a special task, and you have to provide the correspinng queries yourself ... which are different for different dbms systems. So using the normal way would be recommended.

The platform/driver may have some generig helper methods providing some native sql parts for doing stuffs like that. The may be possible to provide custom stuff based on SchemaMigrator or SchemaManger etc - but thats low-level stuff.

doctrine/dbal directly do not really provide these DTL as API. And the querybuilder is not meant to be used for that low level stuff at all. That's the wrong tool for such tasks.

You can also change columns of core tables that way, by providing simply the table name and the column defintion only for the field you want to change.

The official way is to handle this with ext_tables.sql and the database schema analyser.

See: https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ExtensionArchitecture/FileStructure/ExtTablesSql.html

The concept of renaming a column could not work:
On installing the extension all new fields are generated (or should be generated if in composer mode). And as the extension should work with the new columns they are already defined.
And before the upgrade wizard could rename a column these columns are existent already which prevents a rename.

In the end I do a content copy enhancing the update query like this:

$queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
                    ->getQueryBuilderForTable('tt_content');

$queryBuilder
    ->update('tt_content')
    ->set('CType', 'newCType')
    ->set('tx_myext_newfield1',$queryBuilder->quoteIdentifier('tx_myext_oldfield1'),false)
    ->set('tx_myext_newfield2',$queryBuilder->quoteIdentifier('tx_myext_oldfield2'),false)
    ->where($queryBuilder
                ->expr()
                ->eq('CType',$queryBuilder->createNamedParameter('oldCType')))
    ->executeStatement();