这个问题是从问题而来的here https://stackoverflow.com/questions/6877226/rewriting-not-in-sub-select-as-join-for-propel and here https://stackoverflow.com/questions/6878380/use-of-propels-addmultiplejoin.
我最近升级到 Propel 1.5,并开始使用它的 Criteria 查询功能。但是,我有一个无法翻译的查询 - 具有多个条件的左连接:
SELECT * FROM person
LEFT JOIN group_membership ON
person.id = group_membership.person_id
AND group_id = 1
WHERE group_membership.person_id is null;
其目的是找到所有不属于指定组的人。以前我使用以下代码来完成此操作:
$criteria->addJoin(array(
self::ID,
GroupMembershipPeer::GROUP_ID,
), array(
GroupMembershipPeer::PERSON_ID,
$group_id,
),
Criteria::LEFT_JOIN);
$criteria->add(GroupMembershipPeer::PERSON_ID, null, Criteria::EQUAL);
我考虑对该组中的所有人执行查询,获取主键并添加NOT IN
在数组上,但似乎没有一种特别简单的方法可以从查找中获取主键,而且看起来不是很优雅。
一篇关于Codenugget.org http://codenugget.org/building-multiple-join-conditions-with-propel详细说明了如何向连接添加额外的条件,我尝试过:
$result = $this->leftJoin('GroupMembership');
$result->getJoin('GroupMembership')
->addCondition(GroupMembershipPeer::GROUP_ID, $group->getId());
return $result
->useGroupMembershipQuery()
->filterByPersonId(null)
->endUse();
不幸的是,“useGroupMembershipQuery”覆盖了左连接。为了解决这个问题,我尝试了以下代码:
$result = $this
->useGroupMembershipQuery('GroupMembership', Criteria::LEFT_JOIN)
->filterByPersonId(null)
->endUse();
$result->getJoin('GroupMembership')
->addCondition(GroupMembershipPeer::GROUP_ID, $group->getId());
return $tmp;
由于某种原因,这会导致由于某种原因执行交叉连接:
SELECT * FROM `person`
CROSS JOIN `group_membership`
LEFT JOIN group_membership GroupMembership ON
(person.ID=GroupMembership.PERSON_ID
AND group_membership.GROUP_ID=3)
WHERE group_membership.PERSON_ID IS NULL
有谁知道为什么会这样做,或者如何在 Propel 1.5 中成功执行此连接,而不必再次求助于 Criteria?