diff --git a/docs/en/reference/dql-doctrine-query-language.rst b/docs/en/reference/dql-doctrine-query-language.rst index 8950c8d4c..2c2e23f9e 100644 --- a/docs/en/reference/dql-doctrine-query-language.rst +++ b/docs/en/reference/dql-doctrine-query-language.rst @@ -1380,7 +1380,13 @@ Given that there are 10 users and corresponding addresses in the database the ex SELECT * FROM address WHERE id IN (1, 2, 3, 4, 5, 6, 7, 8, 9, 10); .. note:: - Changing the fetch mode during a query is only possible for one-to-one and many-to-one relations. + Changing the fetch mode during a query mostly makes sense for one-to-one and many-to-one relations. In that case, +   all the necessary IDs are available after the root entity (``user`` in the above example) has been loaded. So, one +   query per association can be executed to fetch all the referred-to entities (``address``). + + For one-to-many relations, changing the fetch mode to eager will cause to execute one query **for every root entity +   loaded**. This gives no improvement over the ``lazy`` fetch mode which will also initialize the associations on + a one-by-one basis once they are accessed. EBNF