Php 如何在一个查询中从两个相关表和一个不相关表中获取多个计数？

我对我的数据库进行了大量不必要的查询，这会导致第一个字节的时间变慢。我使用的是PHP PDO类包装器版本1.2（测试版）

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我设法使用左联接从相关表中获取计数，但我需要从非相关表中再获得一个结果，我不知道如何做到这一点。有什么建议吗？

我设法用以下方式提出了建议

 $row = $this->baseClass->db->pdoQuery('SELECT a.boosters,a.created_accounts,b.happy_clients  from (SELECT SUM(user_have_group.user_group = 2 ) AS boosters , count(user.id ) AS created_accounts FROM user LEFT JOIN user_have_group ON user_have_group.user_id = user.id ) AS a,(SELECT SUM(boost_order.status="complete") AS happy_clients  FROM boost_order) AS b')->result();

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感谢chris85的帮助

我想你可以使用一个

联合体

再做一次

选择

。只需确保选择的列数相同即可。

 $row = $this->baseClass->db->pdoQuery('SELECT a.boosters,a.created_accounts,b.happy_clients  from (SELECT SUM(user_have_group.user_group = 2 ) AS boosters , count(user.id ) AS created_accounts FROM user LEFT JOIN user_have_group ON user_have_group.user_id = user.id ) AS a,(SELECT SUM(boost_order.status="complete") AS happy_clients  FROM boost_order) AS b')->result();