结果集有一行多列

    1. -- 案例：查询员工编号最小并且工资最高的员工信息
    2. SELECT * 
    3. FROM employees
    4. WHERE (employee_id, salary)=(
    5.     SELECT MIN(employee_id),MAX(salary)
    6.     FROM employees
    7. );
    8. -- ①查询最小的员工编号
    9. SELECT MIN(employee_id)
    10. FROM employees
    12. -- ②查询最高工资
    13. SELECT MAX(salary)
    14. FROM employees
    16. -- ③查询员工信息
    17. SELECT *
    18. FROM employees
    19. WHERE employee_id=(
    20.     SELECT MIN(employee_id)
    21.     FROM employees
    22. )AND salary=(
    23.     SELECT MAX(salary)
    24.     FROM employees
    25. );