invoice_id is blank in ap_trial_balances_gt table

Hello All,

We have a requirement to create a custom Payables Trial Balance Report by copying and customizing the data model to add more columns from ap_invoices_all table. While joining ap_invoices_all with ap_trial_balances_gt (table in standard data model) we found that invoice_id column in ap_trial_balances_gt table is blank.

Raised an Oracle SR on this as invoice_id being a primary key in ap_trial_balances_gt table cannot be blank. But Oracle Support said it's the intended design and not a bug.

We tried joins with other columns like invoice number, creation date, status, amount etc. but there is always a chance of duplicate invoices.