title: Update statement returning single-row subquery returns more than one row
body: <p>I'm new to SQL and I'm stuck with a query.</p>
  
  <p>I have 3 tables employees, departments and salary_paid.
  I'm trying to update bonus column in salary_paid table by giving this condition</p>
  
  <pre><code>give 10% bonus on total salary to the employees who are not in IT departments. 
  </code></pre>
  
  <p>I came up with this query </p>
  
  <pre><code>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')
             ;
  </code></pre>
  
  <p>However it returns this error</p>
  
  <blockquote>
    <p>ORA-01427: single-row subquery returns more than one row</p>
  </blockquote>
  
  <p>I'm completely clueless on this, please help.
  Thanks in advance </p>