MySql存储过程out id返回null

Question

我有一个存储过程，插入到地址表中，它有3个in参数和1个out参数。如果我调出此过程，parametr为null

CREATE DEFINER=`root`@`localhost` 
PROCEDURE `insert_adress`(
                        in d varchar(50),
                        in r varchar(50),
                        in c varchar(50),
                        in adress_text varchar(255),
                        out id int)
BEGIN
    declare disc_id int;
    declare reg_id int;
    declare coun_id int;


if ((select count(*) from district where district.dist like d) <> 0)
    then set disc_id := (select id from district where district.dist like d);
    else
        insert into district(dist) values(d);
        set disc_id := (select max(id) from district);
end if;

if ((select count(*) from region where region.reg like r) <> 0)
    then set reg_id := (select id from region where region.reg like r);
    else
        insert into region(reg) values(r);
        set reg_id := (select max(id) from region);
end if;

if ((select count(*) from country where country.coun like c) <> 0)
    then set coun_id := (select id from country where country.coun like c);
    else
        insert into country(coun) values(c);
        set coun_id := (select max(id) from country);
end if;

insert into adress(district,region,country,adress_text) values(disc_id,reg_id,coun_id,adress_text);
set id := (select max(id) from adress);   
END

我称之为：

set @id = 0;
call mustaqil.insert_adress('test1', 'test1', 'test1', 'test1', @id);
select @id;

Region，Country表有'test1‘行，但out id，disc_id，reg_id，coun_id应该是null。S:存储过程插入行

Answer 1

只需更改设置id := (从地址中选择最大( id ))；将最大(Id)从地址中选择为id；它应该可以工作