问题描述
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 $$
create procedure usp_raise_salaries1(department_name varchar(30))
begin
update employees as e
set salary = salary * 1.05
where (select f@R_502_6447@t_name,salary from employees as e
join departments as d on e.department_id = d.department_id
where d.name = department_name);
end $$
delimiter ;
set @answer = 'Sales';
call usp_raise_salaries(@answer); -- The Workbench gives error at this line.
解决方法
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 ;