SQL2000中，If 後面多個條件，如何連接？

[rockyvan]

如題：SQL2000中，If 後面可否跟多個條件？
多個條件用什麽關鍵字連接?And,Or?

[wzy_love_sly]

if a=b and b=c or c=d and exists(select * from tb)

[dawugui]

如果是与:
if a = 1 and b = 1 and c = 1 ....

如果是或
if a = 1 or b = 1 or c = 1

如果与和或都有,用括号分开
if ( a = 1 and b = 1 ) or c = 1

[free1879]

只要你if 后面的东西是布尔表达式

[free1879]

可以用多个and,or

[you_tube]

用OR的话用括号括起来

[rockyvan]

補充，我建了一個新表，其中一個字段是計算所得值。
基本情況這樣：
條件1：t1，條件2：t2，字段：cc

if t1 not Null and t2 is Null then cc=t1
if t1 is Null and t2 not Null then cc=t2
if t1 not Null and t2 not Null then cc=t1+t2
else cc=Null


大概就是上面的意思，不知道我說清楚了沒有。

[changjiangzhibin]

可以考虑用Case .. when .. then ...end

[wzy_love_sly]

declare @tb table (t1 int,t2 int,cc int)
insert into @tb select 1,2,null


update @tb set cc=case 
when t1 is not null and t2 is null then t1
when t1 is null and t2 is not null then t2
when t1 is not null and  t2 is not null then t1+t2
else null end

select * from @tb

t1 t2 cc
1 2 3

[rockyvan]

SELECT c5 = (
             IF c1 NOT NULL AND c3 IS NULL THEN c1 
             IF c1 IS NULL AND c3 NOT NULL THEN c3 
             IF c1 NOT NULL AND c3 NOT NULL THEN c1 + c3 
             ELSE NULL)
FROM   Test

--這種寫法說IF附近語法錯誤