多个if else 语句的使用

[xiaoxiaoshi]

表中a b c d四列
if **** 取 a AS X
else
if **** 取 b AS Y
else
if **** 取 c AS Y
else 取 d AS X

执行时报错
多个if else 如何 使用啊 请教

[永生天地]

加begin

if 。。。
begin
end
else
begin
end

[jwdream2008]

case when condition1 then a  when condition2  then b when conditon3 then c
else d end as columnname

[xiaoxiaoshi]

其中涉及到 对 几个列的数据的判断 所以必须用if else

[Mr_Nice]

if 
 begin 
 end
else  
      begin
         if 
           begin
           end
         else
           begin
           end
      end

[永生天地]

对于不加 begin end 的，就只对if或else后面第一句作用
if **** 
begin
	取 a AS X
end
else  
begin
	if **** 
	begin 
		取 b AS Y
	end
	else 
	begin
		if **** 
			取 c AS Y
		else 
			取 d AS X
	end
end

[chuifengde]

if else 不能用在语句中，只能用在批处理中，在语句中只能用case when

[xiaoxiaoshi]

(if Len(BaseData2010.dbo.Guest.telephone2) = 11
begin
BaseData2010.dbo.Guest.telephone1 as Y
end
ELSE
begin
BaseData2010.dbo.Guest.telephone1 as L
END)
是这么写吗

[xiaoxiaoshi]

用case when 判断起来太麻烦 了吧

[xiaoxiaoshi]

象我这种 用case when 怎么编写呢 急啊 高手指点

[okgxs]

USE pubs
GO
SELECT
Title,
'Price Range' =
CASE
WHEN price IS NULL THEN 'Unpriced'
WHEN price < 10 THEN 'Bargain'
WHEN price BETWEEN 10 and 20 THEN 'Average'
ELSE 'Gift to impress relatives'
END
FROM titles
ORDER BY price
GO