bcquality/community/knowledge/error-handling/table-event-subscriber-rolls-back-whole-batch.md

bc-version	domain	keywords	technologies	countries	application-area
all	error-handling	table-events oninsert onmodify ondelete transaction rollback commit batch subscriber	al	w1	all

A throw in a table-event subscriber rolls back the whole batch

Contributions welcome — open a PR to refine or extend this article.

Description

Table-trigger event subscribers (OnAfterInsertEvent, OnAfterModifyEvent, OnAfterDeleteEvent, and their OnBefore counterparts) execute synchronously inside the transaction of the write that fired them. Because AL runs on a single implicit transaction with no per-record savepoint, an error raised in such a subscriber rolls back all work since the last COMMIT — not just the record that triggered it. In a batch loop with no intermediate COMMITs, a single failing record discards the entire batch. The intuition that subscriber validation fails only the current record is wrong on the BC platform.

Best Practice

Decide the failure granularity deliberately. If a batch must continue past individual failures, do not throw from the table-event subscriber — collect the error (for example via ErrorInfo/collectible errors) and let the loop continue, or isolate each record's work behind a Codeunit.Run / if Codeunit.Run() then boundary so its failure rolls back only that record. Insert intermediate COMMITs only with full awareness of the durability trade-off.

Anti Pattern

Putting Error/TestField/FieldError validation inside a table-event subscriber and assuming it rejects just the offending record during bulk processing. The first failure unwinds every uncommitted record in the run, turning a one-row data problem into a whole-batch rollback.