关于sql查询，以显示关于新闻源的关注者数据 [英] Regarding sql query to show followers data on newsfeed

问题描述

我正在实施类似twitter.com的类似网站，我有两个表一个有推文信息，另一个有关注者信息，我想显示来自tweet表中的数据在tweet表userid = @ userid以及Followers表userid = FollowTOid。

例如：

在tweet表中用户id = 1并且在关注者表中我想知道userid 1s跟在列表中所以在关注表userid（1）= FollowToid。



bcoz在twitters新闻提要我们可以看到我们自己的推文以及以下推文



所以请告诉我如何在sql中为它编写查询。

I am implementing similar website like twitter.com and i have two table one having tweet information and one having followers information and i want to show data from tweet where in tweet table userid=@userid as well as in Followers table userid=FollowTOid.
for example:
in tweet table user id=1 and in followers table i want to know that userid 1s following list so in follow table userid(1)=FollowToid.

bcoz in twitters news feed we can see our own tweets as well as following tweet

so please tell me how i can write query for it in sql.

推荐答案

看起来你想要将这两个表一起加入如下

It looks like you want to join the two tables together like the following

select t.* from TweetTable t left join FollowerTable F on t.userid = f.followTOid where t.userid = @userid

有不同类型的连接和你的老朋友谷歌，会有很多关于这个主题的信息

There are different types of joins and your old friend google, will have lots of information on this subject

选择*来自Tweet，其中userid in（选择FollowToId from Follow where userid = @ userid）

Select * from Tweet where userid in (select FollowToId from Follow where userid =@userid)

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