Data in sync record not updated after data sync

Question

Hi everyone,

I'm having these 2 tables. For each table I created 1 synced record, in synced record for Leave, I set a many to one relationship with Status, and by contrast, I set a one to many relationship for Status to Leave.

I ran a SQL script in DB to update statusId values to 3 (UPDATE User SET statusId = 3) and when I check again, SELECT * FROM PPL Leave WHERE statusId <> 3 returns 0 result.

After that, I went into PPL Leave synced record and do a fully sync. I'm expect to see the synced record data to be updated to be the same with the table (all statusId = 3), but instead I can see no change in the sync record, and query SELECT * FROM PPL Leave WHERE statusId <> 3 returns 2 results (which I'm assuming after the sync, data in table was updated to be the same as in sync record).

Is this a strange behaviour or did I set up something wrong?

Also, if possible could you explain for me the below options under Write and Delete Related Records meaning?

Thanks for your help!

Mathieu Drouin · Answer

Normally after a DB update, you need to do a full sync of the Record. 
 Writing related records allows you to write a Record and it's children in one single write: https://docs.appian.com/suite/help/24.1/record-type-relationships.html#add-relationships 
 One last note, I don't think your Leave Status Record should have a relationship with Leave. You should only have the many to one relationship between Leave and Leave Status.