Question

我是SQL的新手，我一直坚持查询。

我有3个表员工，部门和salary_paid。我试图通过给出这个条件来更新salary_paid表中的奖励列

give 10% bonus on total salary to the employees who are not in IT departments.

我想出了这个查询

update salary_paid 
set bonus=(select (0.1*total_salary) "Bonus" 
           from salary_paid, departments, employees
           where 
               employees.department_id=departments.department_id and 
               employees.employee_id=salary_paid.employee_id and
               departments.department_name!='IT')
           ;

但是它会返回此错误

ORA-01427：单行子查询返回多行

我对此完全无能为力，请帮忙。提前致谢

Answer 1

您的内部查询(select (0.1*total_salary) "Bonus" from salary_paid返回的值不止一个，因此无法分配给bounus列。

而是尝试使用像这样的连接进行更新

   UPDATE 
    (SELECT salary_paid.bonus as oldBonus, 0.1*salary_paid.total_salary as newBounus
     FROM salary_paid
     INNER JOIN employees
     ON salary_paid.employee_id = employees.employee_id
     INNER JOIN departments
     ON departments.department_id = employees.department_id 
     WHERE departments.department_name != 'IT'
    ) t
    SET t.oldBonus= t.newBounus

Answer 2

试试这个：

UPDATE
    (
        SELECT *
        FROM employees e LEFT JOIN salary_paid sp ON e.employee_id = sp.employee_id
            LEFT JOIN departments d ON d.department_id = e.department_id
    ) t
SET t.bonus = 0.1 * t.total_salary
WHERE t.department_name != 'IT';

您的查询是使用子查询的结果更新表中的所有行。此外，子查询返回多行。设置值时，子查询应始终返回单列的单行在Oracle中，这些问题通过使用join来解决，如上所示。这将使用相应bonus列中的值更新total_salary列。无需使用子查询。

Answer 3

子查询应始终返回单行。但是你使用select查询来到这里多行。所以首先检查您的选择查询。

select (0.1*total_salary) "Bonus" from salary_paid, departments, employees
where employees.department_id=departments.department_id and employees.employee_id=salary_paid.employee_id and departments.department_name!='IT'

此查询应该只有一个结果，但是您正在尝试获取多行。

让我们尝试将 LIMIT 放入您的选择查询

select (0.1*total_salary) "Bonus" from salary_paid, departments, employees
where employees.department_id=departments.department_id and employees.employee_id=salary_paid.employee_id and departments.department_name!='IT' limit 0,1

您需要以这种方式更改您的选择查询。

Answer 4

试试这个

update salary_paid a,departments b, employees c set a.bonus=(0.1*a.total_salary) "Bonus" 
where c.department_id=b.department_id and c.employee_id=a.employee_id and b.department_name!='IT';

CMIIW

Answer 5

我想在hr用户中更新电子邮件并遇到同样的问题然后我认为这对我有用

update (select email as oldemail, substr(first_name,1,1)||''||last_name||''||'@gmail.com' as email from employees
inner join departments
on
employees.department_id= departments.department_id
)t
set t.oldemail=t.email

返回单行子查询的Update语句返回多行

5 个答案: