SELECt t.id, COUNT(p.thread)FROM Threads AS t LEFT OUTER JOIN Posts AS p ON t.id = p.threadGROUP BY t.id
上一篇 SQL语句缩进的良好做法
下一篇 Amazon Redshift:根据表中存在的列列表选择列
版权所有 (c)2021-2022 MSHXW.COM
ICP备案号:晋ICP备2021003244-6号