根据每个月从考勤中获取明星员工记录

Question

我有员工和员工详细信息表。在 Employee 表中，它有 Id(Primary Key), Name, Gender, Joining Date, Department 等列。

在员工详细信息表中，它有 Id(Primary Key), Employee Table Id(Foreign Key), Current Salary, Daily login Time, Daily logout time 等列。

我想要实现的是，找到本月的 STAR 员工。公式是，

• 首先我需要根据月份找到每个员工的出勤率， 我能够做到，以下是结果。

Id	Name	Attendance	Month
1	Ryan	20	January
2	Joanna	19	January
3	Tom	21	January
4	Lucy	10	January
5	Frank	15	January
6	Jane	17	January
7	Robert	11	January
8	Ryan	18	February
9	Joanna	17	February
10	Tom	20	February
11	Lucy	16	February
12	Frank	15	February
13	Jane	17	February
14	Robert	11	February
15	Ryan	22	March
16	Joanna	19	March
17	Tom	11	March
18	Lucy	10	March
19	Frank	15	March
20	Jane	17	March
21	Robert	15	March

• 然后我需要找到当月的最高出勤率，而最低出勤率将减少 15%，如果有任何员工落在此范围内，那么该员工将成为当月的 STAR 员工。

在第二步中，我面临所有问题。我能够获得最高和最低出勤率，但无法比较。

这是我的计算查询：

SELECT MAX(Attendance) AS [Highest Attendance], 
MAX(Attendance) - ( MAX(Attendance) * .15 ) AS [Lowest Attendance], Month
FROM Employee 
GROUP BY Month;

谁能帮我解决这个问题？ 我正在使用 SQL Server 2017。

这里有一些虚拟数据来创建上述场景：

-- create a table
CREATE TABLE Employee (
  Id int PRIMARY KEY,
  Name varchar(100) NOT NULL,
  Attendance int NOT NULL,
  Month varchar(20) NOT NULL
);
-- insert some values
INSERT INTO Employee VALUES (1, 'Ryan', 20, 'January');
INSERT INTO Employee VALUES (2, 'Joanna', 19, 'January');
INSERT INTO Employee VALUES (3, 'Tom', 21, 'January');
INSERT INTO Employee VALUES (4, 'Lucy', 10, 'January');
INSERT INTO Employee VALUES (5, 'Frank', 15, 'January');
INSERT INTO Employee VALUES (6, 'Jane', 17, 'January');
INSERT INTO Employee VALUES (7, 'Robert', 11, 'January');

INSERT INTO Employee VALUES (8, 'Ryan', 18, 'February');
INSERT INTO Employee VALUES (9, 'Joanna', 17, 'February');
INSERT INTO Employee VALUES (10, 'Tom', 20, 'February');
INSERT INTO Employee VALUES (11, 'Lucy', 16, 'February');
INSERT INTO Employee VALUES (12, 'Frank', 15, 'February');
INSERT INTO Employee VALUES (13, 'Jane', 17, 'February');
INSERT INTO Employee VALUES (14, 'Robert', 11, 'February');

INSERT INTO Employee VALUES (15, 'Ryan', 22, 'March');
INSERT INTO Employee VALUES (16, 'Joanna', 19, 'March');
INSERT INTO Employee VALUES (17, 'Tom', 11, 'March');
INSERT INTO Employee VALUES (18, 'Lucy', 10, 'March');
INSERT INTO Employee VALUES (19, 'Frank', 15, 'March');
INSERT INTO Employee VALUES (20, 'Jane', 17, 'March');
INSERT INTO Employee VALUES (21, 'Robert', 15, 'March');

我的预期示例输出如下：

Name	Month	Employee Attendance	Highest Attendance	Lowest Attendance	Status
Ryan	January	20	21	17.85	STAR EMPLOYEE

Answer 1

您可以通过多种方式实现上述方案，但我想使用CTE。公用表表达式 (CTE) 允许您构建和组织 SQL 查询。

WITH calculated_value AS(
    SELECT MAX(Attendance) AS [Highest Attendance], 
    (MAX(Attendance) - ( MAX(Attendance) * .15 )) AS [Lowest Attendance], Month
    FROM Employee 
    group by Month
)
SELECT e.Name, e.Month, e.Attendance as [Employee Attendance], cv.[Highest Attendance],
       cv.[Lowest Attendance], 
       'STAR EMPLOYEE' AS [Status]
FROM calculated_value AS cv
JOIN Employee AS e ON e.Month = cv.Month
WHERE e.Attendance <= cv.[Highest Attendance] AND e.Attendance >= cv.[Lowest Attendance]

注意：加入我不喜欢的月份

Answer 2

我不完全确定您的目标是什么，但是如果您想根据出勤率大于最低要求来应用状态，您可以使用 执行以下操作窗口函数

with m as (
    select *, Max(attendance) over(partition by [month]) HighestAttendance
    from employee
)
select [Name], [Month], Attendance, 
    HighestAttendance, LowestAttendance,
    case when Attendance > LowestAttendance then 'Star employee' else 'you suck' end Status
from m
cross apply(values(HighestAttendance-(HighestAttendance*0.15)))v(LowestAttendance)

Answer 3

大多数计算都可以在子查询中完成。

SELECT 
  [Name]
, [Month]
, Attendance          AS [Employee Attendance]
, AttendanceMax       AS [Highest Attendance]
, AttendanceThreshold AS [Lowest Attendance] 
, CASE 
  WHEN Attendance >= AttendanceThreshold 
  THEN 'STAR EMPLOYEE' 
  END AS Status
FROM
(
  SELECT *
  , [MonthNumber] = CHARINDEX(UPPER(LEFT([Month], 3)),'___JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC') 
  , [AttendanceMax] = MAX(attendance) OVER (PARTITION BY [month])
  , [AttendanceThreshold] = ROUND((1-0.15)*MAX(attendance) OVER (PARTITION BY [month]), 2)
  FROM employee
) q
WHERE Attendance >= AttendanceThreshold
ORDER BY [MonthNumber] ASC, Attendance DESC

姓名 |月 |员工考勤 |出席率最高 |出席率最低 |状态 :----- | :------- | ------------------: | -----------------: | ----------------: | :------------ 汤姆 |一月 | 21 | 21 | 17.85 |明星员工 瑞安 |一月 | 20 | 21 | 17.85 |明星员工 乔安娜 |一月 | 19 | 21 | 17.85 |明星员工 汤姆 |二月 | 20 | 20 | 17.00 |明星员工 瑞安 |二月 | 18 | 20 | 17.00 |明星员工 乔安娜 |二月 | 17 | 20 | 17.00 |明星员工 简 |二月 | 17 | 20 | 17.00 |明星员工 瑞安 |三月 | 22 | 22 | 18.70 |明星员工 乔安娜 |三月 | 19 | 22 | 18.70 |明星员工

dbfiddle here

上的演示