SQL Server 2012 :: Delete / Recreate Identity Column / Fetch Newly Created Values In Update Statement?

I have a four tables called plandescription, plandetail and analysisdetail. The table plandescription has the columns DetailQuestionID which is the primary and identity column and a QuestionDescription column.

The table plandetail consists of the column PlanDetailID which the primary and identity column, DetailQuestionID which is the foreign key attribute of plandescription table and a planID column.

The third table analysisdetail consists of a analysisID which the primary and identity column, PlanDetailID which is the foreign key attribute of plandetail table and a scenario.

Below is the schema of the three tables

I have a two web form that will insert, update and delete data into these three tables in a two transaction. One web form will perform CRUD operations in plandescription and plandetail table. When the user inserts QuestionDescription and planid in this web form, I will insert the QuestionDescription Value in the plandescription table and will generate a DetailQuestionID value and this value is fed to the plandetail table with the planid. Here I will generate a PlanDetailID.

Once this transaction is done, I will show the second web form in which the user enters the scenario and this will be mapped with the plandescription using the PlanDetailID.

This schema cannot be changes as this is the client requirement. When I insert values I don’t have any problem. However when I update existing data, I need to delete existing PlanDetailID in the plandetail table and recreate PlanDetailID data for that DetailQuestionID and planID. This is because, the user will be adding or deleting a planID associated with the QuestionDescription.

Once I recreate PlanDetailID for that DetailQuestionID and planID, I need to update the old PlanDetailID with the new PlanDetailID in the third table analysisdetail for the associated analysisID.

I created a #Temp table called #DetailTable to insert the values analysisID, planid and old PlanDetailID and new PlanDetailID so that I can have them in update statement once I delete the data from plandetail table for that PlanDetailID.

Then I deleted the plandetailid from the plandetail table and recreate PlanDetailID for that DetailQuestionID. During my recreation I fetched the new PlanDetailID’s created into another temp table called #InsertedRows

After this I am running a while loop to update the temp table #DetailTable with the newly created PlanDetailID for the appropriate planID’s. The problem is here. When I have the same number of planID’s for example 2 planID’s 1,2 I will have only two old PlanDetailID and new PlanDetailID for that planID and analysisID.But When I add a new PlanID or remove a existing planID I am getting null value for that newly added or deleted planID. This is affecting my update statement of analysisdetail table as PlanDetailID cannot be null.

I tried to remove the Null value from the #DetailTable by running the update statement of analysis detail in a while loop however its not working.

DECLARE @categoryid INT = 8
DECLARE @DetailQuestionID INT = 1380
/*------- I need the query to run for the below three data.
Here i'm updating my planids that already exists in my database*/
DECLARE @planids VARCHAR(MAX) = '2,4,5'

[code].....