触发器写法

[liyuyu]

有表A(A_1,A_2) 表B(B_1,B_2)
假设update前A_1叫old_A_1，old_A_2
假设update后A_1叫new_A_1，new_A_2
if old_A_2 ='UP' then
UPdate B set B_2='UUUUU' where old_A_1=B_1;

if old_A_2 ='DOWN' then
UPdate B set B_2='DDDDD' where old_A_1=B_1;
if new_A_2='UP' then
UPdate B set B_2='FFFF' where new_A_1=B_1;

if new_A_2='DOWN' then
UPdate B set B_2='GGGG' where new_A_1=B_1;

[fuda_1985]

学习，
正好不会写触发器~~

[wangxuelid]

if new_A_2='DOWN' then --取掉then，
UPdate B set B_2='GGGG' where new_A_1=B_1;

[-狙击手-]

你这逻辑有点问题吧？

[青锋-SS]

create trigger t_1
on a
for update
as
update b set b_2='UUUUU' where a_2='UP' and A_1=B_1
UPdate B set B_2='DDDDD' where A_2 ='DOWN' and old_A_1=B_1;
UPdate B set B_2='GGGG' from inserted i where i.A_2='DOWN' and i.A_1=B_1

[青锋-SS]

[Quote=引用 3 楼 sdhylj 的回复:]
create trigger t_1
on a
for update
as
update b set b_2='UUUUU' from a where a_2='UP' and A_1=B_1
UPdate B set B_2='DDDDD' from a where A_2 ='DOWN' and A_1=B_1;
UPdate B set B_2='GGGG' from inserted i where i.A_2='DOWN' and i.A_1=B_1


[/Quote]

[bqb]

[Quote=引用楼主 liyuyu 的帖子:]
有表A(A_1,A_2) 表B(B_1,B_2)
假设update前A_1叫old_A_1，old_A_2
假设update后A_1叫new_A_1，new_A_2
if old_A_2 ='UP' then
UPdate B set B_2='UUUUU' where old_A_1=B_1;

if old_A_2 ='DOWN' then
UPdate B set B_2='DDDDD' where old_A_1=B_1;
if new_A_2='UP' then
UPdate B set B_2='FFFF' where new_A_1=B_1;

if new_A_2='DOWN' then
UPdate B set B_2='GGGG' where new_A_…
[/Quote]

create trigger t_update on A 
after update
as
begin
update B set B.B_2=case when i.A_2='UP'   then 'UUUUU' 
                        when i.A_2='DOWN' then 'DDDDD'
                        when i.A_2='UP'   and B.B_2='UUUUU'  then 'FFFF' 
                        when i.A_2='DOWN' and B.B_2='DDDDD'  then 'GGGG'  
                 end
from B,inserted i 
where B.B_1=i.A_1
end

[bqb]

create trigger t_update on A 
after update
as
begin
update B set B.B_2=case when A.A_2='UP'   then 'UUUUU' 
                        when A.A_2='DOWN' then 'DDDDD'
                        when A.A_2='UP'   and B.B_2='UUUUU'  then 'FFFF' 
                        when A.A_2='DOWN' and B.B_2='DDDDD'  then 'GGGG'  
                 end
from B,A
where B.B_1=A.A_1
end

[liyuyu]

谢谢bqb，非常谢谢

[wh110]

[Quote=引用 6 楼 bqb 的回复:]
SQL codecreate trigger t_update on A
after update
as
begin
update B set B.B_2=case when A.A_2='UP' then 'UUUUU'
when A.A_2='DOWN' then 'DDDDD'
when A.A_2='UP' and B.B_2='UUUUU' then 'FFFF'
when A.A_2='DOWN' and B.B_2='DDDDD' then 'GGGG'
end
from B,A
where B.B_1=A.A_1
end
[/Quote]