优化sql查询

Question

UPDATE employees
   SET job_id = (SELECT job_id
                   FROM employees
                  WHERE employee_id = 205),
       salary = (SELECT salary
                   FROM employees
                  WHERE employee_id = 205)
 WHERE employee_id = 114;

这是我一直在使用的查询.在这里我使用2个子查询,但它们具有相同的where条件..寻道时间加倍..有没有办法优化整个查询到单个子查询？

提前致谢

Answer 1

如果更新一组列,则可以删除子查询:

UPDATE employees
   SET (job_id, salary) 
        = (SELECT job_id, salary FROM employees WHERE employee_id = 205)
 WHERE employee_id = 114;