mysql - 错误代码: 1241. Workbench, MySQL, cannot resolve the parameters

Question

我正在使用Workbench编写查询。
成功创建了以下过程(没有问题)。
但是当尝试执行功能时，出现此错误:
错误代码:1241。操作数应包含1列
如果有人帮助我，我将非常感激。

delimiter $$
create procedure usp_raise_salaries1(department_name varchar(30))
begin

update employees as e
set salary = salary * 1.05
where (select first_name, salary from employees as e 
join departments as d on e.department_id = d.department_id
where d.name = department_name);


end $$

delimiter ;

set @answer = 'Sales';
call usp_raise_salaries(@answer); -- The Workbench gives error at this line.

Answer 1

您从子查询中获得了很多行，因此需要'IN子句来选择要更新的行

delimiter $$
create procedure usp_raise_salaries1(department_name varchar(30))
begin

update employees as e
set salary = salary * 1.05
where (first_name, salary) IN (select first_name, salary from employees as e 
join departments as d on e.department_id = d.department_id
where d.name = department_name);


end $$

delimiter ;