存儲過程的SQL查詢

Question

我有五個表“ArtBook，Eng，comm，Law，mgt”，每個表都有相同的列，我想通過它的id搜索特定書籍的所有信息，例如 -

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

如果所有表都存儲了不同類別的書籍，則將它們組合回一個表格並添加“類別”列。 由於您所演示的原因，將這樣的分類分類到單獨的表中並不是一個好主意。

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運算符。

(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。 雖然您可能會考慮重組數據的存儲方式，以使這種事情變得更容易。