只有 select id,c2,case when c3>500 then 'aaa' else 'bbbb' end from t1sqlserver里没有你说的语法
select id, c2, case when c3>500 then 'aaa' else 'bbbb' end from t1
select id, c2, case when c3>500 then 'aaa' else 'bbbb' end from t1
select里要用case语句做判断if语句可以这样用 示例 当至少一本书满足这些条件时,这个示例会给出价格在 $10 与 $20 之间的传统烹调书的列表。否则,SQL Server 会给出一条信息,说明没有书满足这个条件,并生成价格低于 $10 的传统烹调书的列表。USE pubs GO DECLARE @msg varchar(255) IF (SELECT COUNT(price) FROM titles WHERE title_id LIKE 'TC%' AND price BETWEEN 10 AND 20) > 0
BEGIN SET NOCOUNT ON SET @msg = 'There are several books that are a good value between $10 and $20. These books are: ' PRINT @msg SELECT title FROM titles WHERE title_id LIKE 'TC%' AND price BETWEEN 10 AND 20 END ELSE BEGIN SET NOCOUNT ON SET @msg = 'There are no books between $10 and $20. You might consider the following books that are under $10.' PRINT @msg SELECT title FROM titles WHERE title_id LIKE 'TC%' AND price < 10 END下面是结果集:There are several books that are a good value between $10 and $20. These books are: title ------------------------------------------------------------------------ Fifty Years in Buckingham Palace Kitchens Sushi, Anyone?(2 row(s) affected)
select id,c2,case when c3>500 then 'aaa' else 'bbbb' end from t1sqlserver里没有你说的语法
c2,
case when c3>500 then
'aaa'
else
'bbbb'
end
from t1
c2,
case when c3>500 then
'aaa'
else
'bbbb'
end
from t1
示例
当至少一本书满足这些条件时,这个示例会给出价格在 $10 与 $20 之间的传统烹调书的列表。否则,SQL Server 会给出一条信息,说明没有书满足这个条件,并生成价格低于 $10 的传统烹调书的列表。USE pubs
GO
DECLARE @msg varchar(255)
IF (SELECT COUNT(price)
FROM titles
WHERE title_id LIKE 'TC%' AND price BETWEEN 10 AND 20) > 0
BEGIN
SET NOCOUNT ON
SET @msg = 'There are several books that are a good value between $10 and $20. These books are: '
PRINT @msg
SELECT title
FROM titles
WHERE title_id LIKE 'TC%' AND price BETWEEN 10 AND 20
END
ELSE
BEGIN
SET NOCOUNT ON
SET @msg = 'There are no books between $10 and $20. You might consider the following books that are under $10.'
PRINT @msg
SELECT title
FROM titles
WHERE title_id LIKE 'TC%' AND price < 10
END下面是结果集:There are several books that are a good value between $10 and $20. These books are:
title
------------------------------------------------------------------------
Fifty Years in Buckingham Palace Kitchens
Sushi, Anyone?(2 row(s) affected)