Question

我有五个表“ArtBook，Eng，comm，Law，mgt”，每个表都有相同的列，我想通过它的id搜索特定书籍的所有信息 e.g -

select * from ArtBook,Eng,Comm,Law,mgt where @BookId=ArtBooks.BookId
or @BookId=CommBooks.BookId
or @BookId=Eng.BookId
or @BookId=Law.BookId
or @BookId=mgt.BookId

Answer 1

如果所有表都存储了不同类别的书籍，则将它们组合回一个表格并添加“类别”列。根据你所展示的原因，将这样的分类分类到单独的表中并不是一个好主意。

Answer 2

select * 
from ArtBook
where BookId = @BookId
union all
select * 
from Eng
where BookId = @BookId
union all
select * 
from Comm
where BookId = @BookId
union all
select * 
from Law
where BookId = @BookId
union all
select * 
from Mgt
where BookId = @BookId

Answer 3

可以使用UNION或UNION ALL运算符。

(SELECT * FROM ArtBook)
UNION ALL
(SELECT * FROM Eng)
...
WHERE @BookId=ArtBooks.BookId or
       @BookId=CommBooks.BookId or 
       @BookId=Eng.BookId or 
       @BookId=Law.BookId or 
       @BookId=mgt.BookId

等等，等等。虽然您可能会考虑重组数据的存储方式，以使这种事情变得更容易。

存储过程的SQL查询

3 个答案: