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我在 zend 中进行开发并且有一个相当大的 mysql 查询。查询工作正常，我得到了我期望的列表。我正在使用 Select->Where.... 下面是查询。

SELECT DISTINCT `d`.* FROM `deliverable` AS `d` INNER JOIN `groups` AS `g1` ON d.id = g1.deliverable_id INNER JOIN `groupmembers` AS `gm1` ON g1.id = gm1.group_id LEFT JOIN `connection` AS `c` ON d.id = c.downstreamnode_id LEFT JOIN `deliverable` AS `d1` ON c.upstreamnode_id = d1.id INNER JOIN `deliverable` AS `d2` ON CASE WHEN d1.id IS NULL THEN d.id ELSE d1.id END = d2.id INNER JOIN `groups` AS `g` ON d2.id = g.deliverable_id INNER JOIN `groupmembers` AS `gm` ON g.id = gm.group_id WHERE (g1.group_type = 100) AND (gm1.member_id = 1) AND (c.downstreamnode_id IS NULL OR d.restrict_access = 1) AND (g.group_type = 100 OR g.group_type = 110) AND (gm.member_id = 1) AND (d.deliverable_type = 110 OR d.deliverable_type = 100) GROUP BY CASE WHEN c.downstreamnode_id IS NULL THEN d.id ELSE c.downstreamnode_id END

唯一的问题是当我尝试计算 mysql 查询中的行时，我只返回 1。下面是查询

SELECT DISTINCT count(*) AS `rowCount` FROM `deliverable` AS `d` INNER JOIN `groups` AS `g1` ON d.id = g1.deliverable_id INNER JOIN `groupmembers` AS `gm1` ON g1.id = gm1.group_id LEFT JOIN `connection` AS `c` ON d.id = c.downstreamnode_id LEFT JOIN `deliverable` AS `d1` ON c.upstreamnode_id = d1.id INNER JOIN `deliverable` AS `d2` ON CASE WHEN d1.id IS NULL THEN d.id ELSE d1.id END = d2.id INNER JOIN `groups` AS `g` ON d2.id = g.deliverable_id INNER JOIN `groupmembers` AS `gm` ON g.id = gm.group_id WHERE (g1.group_type = 100) AND (gm1.member_id = 1) AND (c.downstreamnode_id IS NULL OR d.restrict_access = 1) AND (g.group_type = 100 OR g.group_type = 110) AND (gm.member_id = 1) AND (d.deliverable_type = 110 OR d.deliverable_type = 100) GROUP BY CASE WHEN c.downstreamnode_id IS NULL THEN d.id ELSE c.downstreamnode_id END

我通过使用生成第一个查询的相同“选择”来生成它，但我重置了列并添加了计数。

$this->getAdapter()->setFetchMode(Zend_Db::FETCH_ASSOC);
    $select
        ->reset( Zend_Db_Select::COLUMNS)
        ->columns(array('count('.$column.') as rowCount'));
    $rowCount = $this->getAdapter()->fetchOne($select);

这种方法适用于我所有其他查询，只有我遇到问题的这个。我怀疑它与我在那里的“案例”有关，但这很奇怪，因为我在第一个查询中得到了正确的行。有任何想法吗。谢谢。

仅供参考，以下是我成功工作的两个查询。

SELECT DISTINCT `po`.* FROM `post` AS `po` INNER JOIN `postinfo` AS `p` ON po.postinfo_id = p.id WHERE (p.creator_id = 1) ORDER BY `p`.`date_created` DESC

SELECT DISTINCT count(*) AS `rowCount` FROM `post` AS `po` INNER JOIN `postinfo` AS `p` ON po.postinfo_id = p.id WHERE (p.creator_id = 1) ORDER BY `p`.`date_created` DESC

在这一个中，我在第一个查询中返回了 4 行，第二个查询返回了“int 4”。有谁知道为什么它不适用于大查询？

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3 回答 3

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好的，它是 GROUP BY 导致只返回 1 个结果。感谢 Interrobang 的帮助，我敢肯定，错误地使用 DISTINCT 将来会让我头疼。

于 2012-03-16T11:29:20.007 回答
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移动你的DISTINCT.

SELECT COUNT(DISTINCT `po`.*) AS `rowCount` ...
于 2012-03-15T21:57:40.363 回答
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尝试在查询中使用 SQL_CALC_FOUND_ROWS？ http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_found-rows

使用 SQL_CALC_FOUND_ROWS 是 mysql 特定的，但即使您的初始查询包含限制，它也能很好地获取完整的记录计数。获得计数后，不要在后续查询中包含 SQL_CALC_FOUND_ROWS 以获取额外记录，因为这会导致查询的额外负载。

您的初始查询将是：

SELECT SQL_CALC_FOUND_ROWS  DISTINCT `d`.* FROM `deliverable` AS `d` INNER JOIN `groups` ...

在执行初始查询后，您必须进行后续调用以通过执行SELECT FOUND_ROWS().

如果您稍微搜索一下，您会发现有人扩展了 Zend_Db_Select 以包含此功能。

于 2012-03-17T17:12:11.903 回答