抱歉，标题不明确。
我正在 PHP 上使用 MySQL。
这些是我的表格:
+++++++++++++++++++++++
|........thread.......|
+++++++++++++++++++++++
|.id.|..title..|..ok..|
+++++++++++++++++++++++
|.45.|.baslik.|...1...|
|.53.|.baslik.|...0...|
|.56.|.baslik.|...1...|
+++++++++++++++++++++++
+++++++++++++++++++++++++++++++++
|............comment............|
+++++++++++++++++++++++++++++++++
|.id.|..text..|.ok.|.thread_id..|
+++++++++++++++++++++++++++++++++
|.1..|.falan..|.0..|....45......|
|.3..|.filan..|.1..|....56......|
+++++++++++++++++++++++++++++++++
我需要的是获取“thread”表的所有已检查(ok=1)行，其行数提供 thread.id = comment.thread_id 和 comment.ok=1 的相等性。
当我使用以下查询时，我会得到选中或未选中的所有评论计数。
select thread.*, count( comment.thread_id ) as countComment from `thread` left join `comment` on thread.id=comment.thread_id where thread.ok='1' group by thread.id
我想要得到的输出必须如下所示。
++++++++++++++++++++++++++++++++++++
|.id.|.title..|..ok.|.commentCount.|
++++++++++++++++++++++++++++++++++++
|.45.|.baslik.|...1.|......0.......|
|.56.|.baslik.|...1.|......1.......|
++++++++++++++++++++++++++++++++++++
谢谢
最佳答案
试试这个:
LEFT JOINcommentON thread.id = comment.thread_id AND comment.ok = '1'
关于php - 我无法构建 SQL 查询(连接)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/11702447/