php - mysql 和 php - 一次选择获得 3 个或更多表？

Question

我想向我的用户展示他最近的事件。为此，我有 3 个表格，我想按新闻日期显示顺序。

例如:

You sell product Y (table sell)
UserX put your product Y in favorite list (table favorite)
You have a product question (table questions)
You sell product Y (table sell again)
...

所以我想从不同的表中获取用户事件(卖家)并为他显示此警报。是否可以？任何例子如何做到这一点？

表卖:

id
seller
customer
product_name
data

最喜欢的表:

product_id
seller
customer
data

表格问题:

product_id
seller
customer
question
answer
data

Answer 1

我假设期望输出中的 You 表示卖家，userX 表示客户。所以，我认为这对你有用:

select data,concat('You sell product ',product_name) as logs 
from sell 
where seller = 'userid'
union all
select data,concat(customer,' put your product ',product_id,' in favourite list') 
from favorite 
where seller = 'userid'
union all
select data,concat('You have a product question') 
from question
where seller = 'userid'
order by data desc