doctrine-orm - 从 $query->setMaxResults() 获取奇怪的行为

Question

当我在查询上调用 setMaxResults 时，它似乎想将最大数字视为“2”，无论它的实际值是多少。

function findMostRecentByOwnerUser(\Entities\User $user, $limit)
{
    echo "2: $limit<br>";
    $query = $this->getEntityManager()->createQuery('
        SELECT t
        FROM Entities\Thread t
        JOIN t.messages m
        JOIN t.group g
        WHERE 
            g.ownerUser = :owner_user
        ORDER BY m.timestamp DESC
    ');
    $query->setParameter("owner_user", $user);
    $query->setMaxResults(4);
    echo $query->getSQL()."<br>";
    $results = $query->getResult();
    echo "3: ".count($results);
    return $results;
}

当我注释掉 setMaxResults行，我得到 6 个结果。当我把它留在里面时，我会得到 2 个最近的结果。当我在 phpMyAdmin 中运行生成的 SQL 代码时，我得到了 4 个最近的结果。生成的SQL，供引用，为:

SELECT <lots of columns, all from t0_>
FROM Thread t0_ 
INNER JOIN Message m1_ ON t0_.id = m1_.thread_id 
INNER JOIN Groups g2_ ON t0_.group_id = g2_.id 
WHERE g2_.ownerUser_id = ? 
ORDER BY m1_.timestamp DESC 
LIMIT 4

编辑 :

阅读时 the DQL "Limit" documentation ，我遇到了以下情况:

If your query contains a fetch-joined collection specifying the result limit methods are not working as you would expect. Set Max Results restricts the number of database result rows, however in the case of fetch-joined collections one root entity might appear in many rows, effectively hydrating less than the specified number of results.

我很确定我不是在做一个 fetch-joined 集合。我的印象是 fetch-joined 集合是我做类似 SELECT t, m FROM Threads JOIN t.messages 的地方。 .我对此的理解不正确吗？

Answer 1

更新:使用 Doctrine 2.2+，您可以使用分页器 http://docs.doctrine-project.org/en/latest/tutorials/pagination.html