UC知道Sql 2005 简单的两个表连接问题.?
来源：百度知道 编辑：UC知道 时间：2024/06/18 10:33:27
假如,我用sql server 查询数据.!
遇到两个表查询问题.! 就是用Count 函数统计数据;
select (B.B_ID,B.B_Name,BT.BK_Name from dbo.Book as B inner join dbo.BookType as BT
on(B.B_Type=BT.BK_ID)) where (BK_Name='自然科学')
我要用Count统计函数, 统计 '自然科学' 类型的图书有多少.?
Count函数,该怎么写..!
遇到两个表查询问题.! 就是用Count 函数统计数据;
select (B.B_ID,B.B_Name,BT.BK_Name from dbo.Book as B inner join dbo.BookType as BT
on(B.B_Type=BT.BK_ID)) where (BK_Name='自然科学')
我要用Count统计函数, 统计 '自然科学' 类型的图书有多少.?
Count函数,该怎么写..!
这个比较简单，就是对查询出来的结果在包一层，并使用count函数就可以了，
具体的SQL语句如下：
select count(*)
from
(
select (B.B_ID,B.B_Name,BT.BK_Name from dbo.Book as B inner join dbo.BookType as BT
on(B.B_Type=BT.BK_ID)) where (BK_Name='自然科学')
) as temp
呵呵，希望能有帮助，^_^
select (B.B_ID,B.B_Name,count(BT.BK_Name) from dbo.Book as B inner join dbo.BookType as BT on(B.B_Type=BT.BK_ID)) where (BK_Name='自然科学') group by B.B_ID,B.B_Name
试试 ^_____^
select (B.B_ID,B.B_Name,BT.BK_Name from dbo.Book as B inner join dbo.BookType as BT
on(B.B_Type=BT.BK_ID)) ,count(bk_Name) where (BK_Name='自然科学')
加一个count(bk_Name)就可以啦