informix里怎么写触发器?

[VCSQLVB]

简单的处理: 新增记录时,比较varchar字段knh和kh的内容，把内容长的放kh里（也就是更新原来的内容）。

[VCSQLVB]

create trigger tig_cmp
insert on zxf
referencing new as q
for each row
(
when(length(q.c2)>length(q.c1))
(
update zxf set q.c1=q.c2 where c2=q.c2
)
)
也错的,晕]


谁知道嘛,谢谢

[rabbitjump]

网上例子很多，INFORMIX书上也有
create table temp_trig
(a serial,
b integer,
c integer);


CREATE PROCEDURE output_by_input(v_input integer) RETURNING integer;
RETURN v_input;
END PROCEDURE;

drop trigger tr_tmp_trig_i ;

create trigger tr_tmp_trig_i insert on temp_trig
referencing new as new
for each row
(
execute procedure output_by_input(new.a) into c
);

insert into temp_trig (b) values (2);

[apple_01]

使用AFTER FIELD應該可以的

[VCSQLVB]

CREATE TRIGGER tig_is_zxf
insert ON zxf
referencing new as q
after(
when(len(q.knh) > len(q.kh))
(
update zxf set q.kh = q.knh where knh = q.knh
)
)

老说语法错误,我以前没写过informix,有谁知道呀,帮忙写一个.
谢谢