SQL：查找在一周中的特定日期雇用的所有员工

Question

我很难找到在一周中招聘率最高的一天（周一、周二等）录用的所有员工。

例如：如果星期一是雇用人数最多的一天，我想显示一周中这一天雇用的所有员工。

我发现哪些日子招聘人数最多：

SELECT COUNT(*), TO_CHAR(HIRE_DATE,'DAY') DAY
FROM EMPLOYEES
GROUP BY TO_CHAR(HIRE_DATE,'DAY')
HAVING COUNT (*)=(SELECT MAX(COUNT(*))FROM EMPLOYEES GROUP BY TO_CHAR(HIRE_DATE,'DAY'));

但我无法显示当天雇用的所有员工。提前感谢您的宝贵时间。

Answer 1

我不知道 Oracle 语法，但在该查询中加入 EMPLOYEES。类似于：

SELECT  e.*
FROM EMPLOYEES e
INNER JOIN
    (SELECT <employee id>, TO_CHAR(HIRE_DATE,'DAY') DAY
    FROM EMPLOYEES
    GROUP BY TO_CHAR(HIRE_DATE,'DAY')
    HAVING COUNT (*)=(SELECT MAX(COUNT(*))FROM EMPLOYEES GROUP BY TO_CHAR(HIRE_DATE,'DAY'))) AS empdays
    ON TO_CHAR(e.HIRE_DATE, 'DAY') = empdays.DAY;

Answer 2

怎么样：

select * from employees
where to_char(HIRE_DATE,'DAY') in

SELECT TO_CHAR(HIRE_DATE,'DAY') DAY
FROM EMPLOYEES
GROUP BY TO_CHAR(HIRE_DATE,'DAY')
HAVING COUNT (*)=(SELECT MAX(COUNT(*))FROM EMPLOYEES GROUP BY TO_CHAR(HIRE_DATE,'DAY'));