Overview: When performing an Inventory single record overlay, data import handles the data elements of the Instance itself, but it seems to ignore the external relationships that the instance might have to other instances - like preceding/succeeding titles or the less used parent-child relationships. This information is stored separately from the Instance and the overlay logic must know about these data and deal with them specifically. quickMARC and Data Import updates show the same behavior

Workarounds: None. quickMARC displays the same behavior. If a 785 is added to the Jewish currents record, the SRS MARC is updated and View source shows the Succeeding title, but the Succeeding title is not added to the Instance.

Steps to reproduce:

1. Login to FOLIO Snapshot, as user Diku_Admin

2. Go to Settings, check the Z39.30 target profile for import of OCLC records are enabled, and the authentication is set 100473910/PAOLF

3. Go to Inventory, and click on the Actions menu and import from OCLC Worldcat a record with OCLC identifier number: 183425387 (a serial with the Resource title: Jewish currents, and Preceding title: Jewish life)

4. Verify the imported record in Inventory (instance) and in SRS - here you see the Preceding title in 780.

5. Overlay this newly imported record with the record having: OCLC identifier number: 1145719992 (a monograph with the Resource title: Butterflies in the snow?, and no Preceding title)

Expected result:
The Monograph title Butterflies in the snow? do a complete overlay, while no MARC field has been field protected.

Actual result:
The Preceding title from the first import (Resource title: Jewish currents.) Jewish life is kept in the updated Instance, which is not intended. When viewing the Source MARC record from the Instance, the SRS MARC has been changed completely to the Butterflies record, and no longer has a 780 field for Jewish life.

Related scenarios (maybe create TestRails for all of these)

1. Import the Jewish life record, either via Inventory single record import or Data Import default profile. Manually edit the record via quickMARC to add a succeeding title field (785). Save the changes. View instance and SRS MARC. The SRS MARC shows the succeeding title, but the Instance does not. If the SRS MARC is exported, it contains the 785 field. Covered by MODINV-445

2. Import the Jewish life record, either via Inventory single record import or Data Import default profile. Manually edit the record via quickMARC to delete the 780 field. Save the changes. View instance and SRS MARC. The SRS MARC does not have the 780 field any more, but the Instance still has a Preceding title. If the SRS MARC is exported, it does not contain the 780. Covered by MODINV-445

3. Import the Jewish life record via Data Import default profile. Export the record using the default MARC profile. Manually edit the record outside of FOLIO to add a 785 or remove the 780. The re-import the MARC Bib, matching on the 001 HRID or 999 ff $i or 999 ff $s, and updating the instance with a new status. View the updated instance and View source. MARC record will match what was imported. Instance preceding/succeeding data will not have changed

Other comments:
In this particular case, it seems the logical choice would be to delete the relationship (in the db table 'preceding_succeeding_title'), since this Instance appears to be an entirely new title, which would not have the same (or any) preceding/succeeding titles as the old one. But I suppose there could just as easily be Instance updates, where you don't switch out the entire title but just update elements of it, and where the Instance's existing preceding / succeeding title relations should thus be retained. The overlay logic would need to know about this, to get it right.