使用现有视图进行派生表查询

Question

您好，我是Sql的新手，有人可以帮我处理派生表。我有一个现有视图作为起点，应从该视图开始构建查询，以根据当前查询逻辑为派生表提供所有雇员和联系人列设置雇员链接表的主键和外键。谢谢

   --- Here is the view for the required table

    With Columns as
    ( 
    select EC.Emp_ID
    ,EC.EmpCode_ER_ID
    ,EC.EmpCode
    ,EC.JoiningDate_Date_ID
    ,EC.JoiningDate_Time_ID
    ,row_number() over (partition by EC. Emp_ID order by EC.JoiningDate_Date_ID Desc,
    EC.JoiningDate_Time_ID Desc) As EmpRef
    From Tmp.Employee AS EC

    Where EC. EmpCode
    In (‘abc’,’ccc’,’aaa’,’dca’)
    )
    Select CH. EmpID as Employee_Ref_ID
    ,CH. EmpCode_ET3_ID as TypeOfEmployee_EmpCode_ID
    ,CH. EmpCode as TypeOfEmployee_EmpCode
    ,C.CTV3Text as Emp_Descriptn_Text
    ,case when C.EmpCode = ‘abc’ then ‘A’
     When C.EmpCode = ‘ccc’ then ‘B’
     When C.EmpCode = ‘aaa’ then ‘C’
     When C.EmpCode = ‘dca’ then ‘D’
    End as Employee_DatabaseCode
    ,CH. JoiningDate_Date_ID
    ,CH.JoiningDate_Time_ID
    From columns as CH
    Inner join Tmp.Employee AS T
        On CH. EmpCode_ET3_ID = C.ID
    Where CH.EmpRef  = 1;