need help with cross referenced tables
I have set of records where when users selects particular records the i insert all the record ids to new table(A) with with category id
Table A
id --- record_id---category_id --
With every record_id there are many small tasks associated (1 to many).
SO based upon inserted record_ids i also insert task_id in Table B
Table B
id-----record_id-------Task_id -----category_id
This is when user creating new category
THe problem is when user want to edit the category and selects different record_ids , then i have two solutions
1)Either delete all records with that category_id and insert new record ids
But then i also have to delete Table B records also
2) Second is check if record is already there if not inseret it otherwise update it.
But how will i delete those records which were previously present but not now
e,g Initially i had Record_ids = 3,4,5,6,7
New Record_ids = 1,2,3,4
Now i want to add 1,2 and delete 5,6,7 from table
Also i don't know how to deal with Table B task which are realted to those records
Because i have to delete tasks related to record_d , 5,6,7 and then insert tasks for record_id 1,2
Any help please
Also if user has not chnaged anhthing then i don't want that first i should delete all the records and then again insert it
so please help me