标题: 请教pl/pgsql的 IF 语句的疑问 [打印本页] 作者: lunarwildgoose 时间: 2010-03-15 20:10 标题: 请教pl/pgsql的 IF 语句的疑问 if expression1 then
if expression2 then
statements1
end if;
else
statements2
end if;
若是expression1判断问真,而expression2判断为假,应该是返回错误才对吧?
可是我对下面的函数很不理解,请大侠赐教!谢谢
create function change_prov(char(8),char(6))
returns text as
$
declare f_name alias for $1;
f_prov alias for $2;
f_rec record;
message text;
begin
if length(f_prov)!=0 then
select * into f_rec from friend where name=f_name;
if not found then
insert into friend (name,prov) values (f_name,f_prov);
message:='数据插入成功';
return message;
else update friend set prov=f_prov where name=f_name;
message:='省市名更新成功';
return message;
end if;
else select * into f_rec from friend where name=f_name;