假设有两个表:
表A.
messageID / Message / More..
1 / This is the first message / Etc..
2 / This is the second message / Etc..
3 / This is the third message / Etc..
表B
commentID / messageID / Comment
1 / 2 / This is a comment to the second message
2 / 2 / This is another comment to the second message
3 / 3 / This is a comment to the third message
表之间的关系是messageID字段.
我想要一个生成这样的结果的查询,其中我从表A中提取所有字段,以及表B中每条消息的注释数计数,如下所示: …