当 Archived_Date 为 NULL 并在 Age 列中返回 NULL 值时未计算 Statement Age 的情况

Question

CASE    
    WHEN Isconverted = 'TRUE'    THEN DATEDIFF(DAY, Task_CreatedDate, OPP.CreatedDate)
    WHEN Isconverted = 'FALSE'   THEN DATEDIFF(DAY, Task_CreatedDate, A.Archived_Date)
    WHEN A.Archived_Date IS NULL THEN DATEDIFF(DAY, Task_CreatedDate, GETDATE())
    ELSE 'NULL'
END AS 'Age'

** Above case when statement is not calculating third line when Archive_Date is null I need the age column to be populated with current date - Task_CreatedDate **

Answer 1

I assume for the cases that A.Archived_Date IS NULL, Isconverted is either true or false, so one of first two cases will be picked always.

so if that is a priority over those you need to put it as the first case:

CASE    
    WHEN A.Archived_Date IS NULL THEN DATEDIFF(DAY, Task_CreatedDate, GETDATE())
    WHEN Isconverted = 'TRUE'    THEN DATEDIFF(DAY, Task_CreatedDate, OPP.CreatedDate)
    WHEN Isconverted = 'FALSE'   THEN DATEDIFF(DAY, Task_CreatedDate, A.Archived_Date)
    ELSE 'NULL'
END AS 'Age'

Answer 2

I think you want:

(CASE WHEN Isconverted = 'TRUE'
      THEN DATEDIFF(DAY, Task_CreatedDate, OPP.CreatedDate)
      ELSE DATEDIFF(DAY, Task_CreatedDate, COALESCE(A.Archived_Date, GETDATE()))
 END) AS Age

Answer 3

You can simplify your code by placing the CASE expression inside the DATEDIFF() function, where you can use COALESCE() to check if A.Archived_Date is NULL :

DATEDIFF(
  DAY, 
  Task_CreatedDate, 
  CASE WHEN Isconverted = 'TRUE' THEN OPP.CreatedDate ELSE COALESCE(A.Archived_Date, GETDATE()) END
) AS Age