How Do I Prevent an Object Group from Adding Lines?

I have a scenario say once end user selects / enter a value in a field, I need to fetch records for that corresponding selected value and show the records in an object group.

This is working fine if I keep an auto post back to true on the selection field and do a DB integration to fetch the records based on the selection.

1. The problem I am facing is, say initially user selects a value ‘100’ and now the object group is populated with all records matching ‘100’. Now user selects ‘101’ and now my object group is refreshed with all the existing records of ‘100’ and added new records for ‘101’ selection.
   So my object group is now having both the records matching ‘100’ and ‘101’.
   But I only need records for ‘101’ in this case.
2. If I have any other postbacks on the form even after the change of those fields my object group is getting refreshed and adding duplicate lines to the end of the object group.

Say I initially selected value ‘100’ so my object group has all records matching ‘100’.
Now, I haven’t changed the selection ‘100’, but have modified some other column for which autopostback is set to true.
Now my object group got refreshed and I have duplicate (twice) records in the object group for the selection ‘100.
I want to restrict my object group to be refreshed only when there is a change in the selection of a certain field but not on change of other fields.

Answer

For Step 1, change your Object Group integration mode to ‘Replace Lines’ as shown in the image below.

For Step 2, create a Last valve holder control which is hidden, in the wizard add a condition for the integration to only run if last value is not same as new.