Question

您能告诉我们如何从表格中查找该雇员的最新更新职位吗？两个表：Employee和EmployeeDetails。员工字段为：EmployeeID，EmployeeName员工详细信息字段为：EmployeeID，指定，PromotionDate。

如果提供EmployeeID，如何查找当前的雇员指定。使用功能。我想创建一个简单的函数来使用EmployeeID根据当前的指定（最新的PromotionDate）获得指定，然后与Employee表联接。

DROP TABLE IF EXISTS Employee

CREATE TABLE Employee
(
    EmployeeID INT NOT NULL PRIMARY KEY IDENTITY(1000,1),
    EmployeeName VARCHAR(25)
)

INSERT INTO Employee VALUES('AAA');
INSERT INTO Employee VALUES('LAAA');
INSERT INTO Employee VALUES('RSSS');
INSERT INTO Employee VALUES('SEEE');
INSERT INTO Employee VALUES('CFFF');
INSERT INTO Employee VALUES('SEEEW');
INSERT INTO Employee VALUES('MCCC');
INSERT INTO Employee VALUES('DERR');
INSERT INTO Employee VALUES('DERR');
INSERT INTO Employee VALUES('DERW');

SELECT * FROM Employee

DROP TABLE EmployeeDetails

CREATE TABLE EmployeeDetails
(
   EmployeeID INT FOREIGN KEY REFERENCES Employee(EmployeeID),
   Designation VARCHAR(25),
   PromotionDate Date
)

INSERT INTO EmployeeDetails VALUES(1000,'www','2020-11-20');
INSERT INTO EmployeeDetails VALUES(1000,'qqq','2020-01-23');
INSERT INTO EmployeeDetails VALUES(1009,'qqq','2020-09-20');


SELECT * FROM  EmployeeDetails

SELECT
    E.EmployeeID,
    E.EmployeeName,
    ED.Designation, ED.PromotionDate
FROM 
    Employee E 
JOIN  
    EmployeeDetails ED ON E.EmployeeID = ED.EmployeeID

我为此编写了一个函数，但是我不知道如何将其与查询合并：

 CREATE FUNCTION GetOnlyTheCurrentPost
( @EmpID INT)
RETURNS DATE
AS
BEGIN
DECLARE @PromoDate DATE
SELECT @PromoDate= MAX(PromotionDate)
FROM EmployeeDetails
WHERE EmployeeID = @EmpID
 RETURN(@PromoDate)
END

我如下更改了功能

ALTER FUNCTION [dbo].[GetOnlyTheCurrentPost]
( @PromoDate DATE)
RETURNS DATE 
AS
BEGIN
SELECT  @PromoDate= MAX(PromotionDate)
FROM EmployeeDetails 
RETURN(@PromoDate)
END

SELECT
    E.EmployeeID,
    ED.Designation,[dbo].[GetOnlyTheCurrentPost](ED.PromotionDate) AS LatestPost
FROM
    Employee E
JOIN
     EmployeeDetails ED
     ON E.EmployeeID = ED.EmployeeID

这不仅会显示所有记录，而且还会显示所有记录。

再次，我更改了功能。如果我给EmployeeID像SELECT [dbo].[GetOnlyTheCurrentDesignation](1011)，我想得到当前的名称。输出应根据给定的相应EmployeeID输出进行打印：ProjectManager

    ALTER FUNCTION GetOnlyTheCurrentDesignation
(@EmpID INT)
RETURNS VARCHAR(MAX) 
AS
BEGIN
DECLARE @Designation VARCHAR(25)
SELECT @Designation=Designation, MAX(PromotionDate)
FROM EmployeeDetails
WHERE EmployeeID = @EmpID
 RETURN(@Designation)
END

请告诉我解决此问题的方法

Answer 1

尝试这样的事情：

Timer.run

使用FUNCTION -SQL Server查询来查找员工的当前职位

1 个答案: