Question

我正在创建一个检索客户端信息的过程，那就是有两种类型的客户端具有不同的属性，所以我需要一个不同的查询返回值，具体取决于将其与父项连接的客户端类型table ...我做了这个，但显然我犯了一些语法错误：

delimiter &
create procedure show_Client(in id varchar(10)) 
begin 
if (exists (select ID from CLIENT_1 as C1 where id =C.ID),1,0) 
then 
begin 
select * from CLIENT_1 as C1 join CLIENT C on C1.ID=C.ID where C1.ID=id; 
end; 
else 
BEGIN 
select * from CLIENT_2 as C2 join CLIENT C on C2.ID=C.ID where C2.ID=id; 
end; 
end if; 
&

Answer 1

您没有终止第一个begin。

如果一致地缩进代码，则更容易看到错误：

delimiter &

create procedure show_Client(in id varchar(10)) 
begin 
    if (exists (select ID from CLIENT_1 as C1 where id =C.ID),1,0) 
    then 
        begin 
            select * from CLIENT_1 as C1 join CLIENT C on C1.ID=C.ID where C1.ID=id; 
        end; 
    else 
        begin 
            select * from CLIENT_2 as C2 join CLIENT C on C2.ID=C.ID where C2.ID=id; 
        end; 
    end if; 
&

您需要与第一个end相同的缩进级别begin。

Answer 2

我修好了！

delimiter &
create procedure show_Client(in id varchar(10)) 
begin 
    if (select exists (select C1.ID from CLIENT_1 as C1 where id=C1.ID)=true) 
    then 
        begin 
            select * from CLIENT_1 as C1 join PARENT_CLIENT as CP on C1.ID=CP.ID where C1.ID=id; 
        end; 
    else 
        begin 
            select * from CLIENT_2 as C2 join PARENT_CLIENT as CP on C2.ID=CP.ID where C2.ID=id; 
        end; 
    end if; 
end
&

谢谢你们！

MySQL正确使用if存在

2 个答案: