SQL Server：更改存储过程以接受参数

Question

Employee表

编写一个 SQL 语句来改变下面提到的预先存在的存储过程以完成以下操作：

• 允许提供包含经理Emp_ID 的参数
• 使用提供的参数来限定查询中的Emp_ID
• 如果未提供参数值，则为参数分配零值
• 将结果语句重写为包含经理姓氏的JOIN

• 确保结果显示如下：

  Manager's Last Name
  Employee's Last Name
  Employees Hire Date
  

• 按经理姓氏、最近雇用的员工和员工姓氏对查询结果排序

这是预先存在的存储过程代码：

CREATE PROCEDURE dbo.sp_GetEmployeeNm 
AS
   SELECT  
       Last_Nm, Hire_Dt
   FROM 
       dbo.Employee
   WHERE 
       Mgr_ID IN (SELECT Emp_ID 
                  FROM dbo.Employee 
                  WHERE Emp_ID = 12345)

有没有人知道如何正确地改变这个存储过程？

这是我尝试过的：

ALTER PROCEDURE dbo.sp_GetEmployeeNm (@Emp_ID INT = 0) 
AS 
BEGIN
    SELECT 
        m.Last_Nm AS Manager's Last Name, 
        e.Last_Nm AS Employee's Last Name, 
        e.Hire_Dt AS Employee's Hire Date
    FROM
        Employee  e
    INNER JOIN 
        Employee m ON e.Emp_ID = m.Mgr_ID
    WHERE 
        e.Emp_ID = 12345
    ORDER BY 
        (m.Last_Nm, e.Hire_Dt, e.Last_Nm) DESC
END

Answer 1

ALTER PROCEDURE dbo.sp_GetEmployeeNm 
    @Emp_ID INT = 0 
AS 
BEGIN
    SELECT 
        m.Last_Nm AS 'Manager''s Last Name', 
        e.Last_Nm AS 'Employee''s Last Name', 
        e.Hire_Dt AS 'Employee''s Hire Date'
    FROM 
        Employee  e
    INNER JOIN 
        Employee m ON e.Emp_ID = m.Mgr_ID
    WHERE 
        e.Emp_ID = @Emp_ID
    ORDER BY 
        (m.Last_Nm, e.Hire_Dt, e.Last_Nm) DESC
END
GO

使用

EXEC dbo.sp_GetEmployeeNm 12345