在 MySQL 中使用带有 PREPARE 的 LIMIT 变量时出现未声明的变量错误

Question

I'm writing a stored procedure. I am having some problems using a variable in combination with LIMIT and a prepared statement. (See code below)

The procedure is created normally, but when I call it I get an error that variable a is undeclared. Any suggestions?

delimiter //
drop procedure if exists shop1;
create procedure shop1()
begin 
    declare a varchar(255) default null;
    declare counter int(4) default 0;
    declare row_numbers int(4); 
    declare s varchar(255) default null;

    select count(*) into row_numbers from salesmen;
    WHILE counter< row_numbers+1 DO
        set @s='select fio from salesmen into a Limit ? 1';
        set @counter=counter;
        prepare stmt from @s;
        execute stmt using @counter;

        SET counter=counter+1;
        insert into warehouse.place (shop, fio) values (1, a);
    END WHILE;

    SET counter=0;
    select count(*) into row_numbers from products;
    WHILE counter< row_numbers+1 DO
        SET counter=counter+1;
    END WHILE;
end; 
//

Answer 1

You could use an INSERT... SELECT to do the same thing -

INSERT INTO warehouse.place (shop, fio)
SELECT 1, fio FROM salesmen

Answer 2

Did you mean?

set @s='select fio from salesmen into a Limit ?,1';