--- bc-version: [15..] domain: events keywords: [getdatabasetabletriggersetup, onaftergetdatabasetabletriggersetup, globaltriggermanagement, global-triggers, ondatabaseinsert, ondatabasemodify, ondatabasedelete, ondatabaserename, change-log, var-parameter] technologies: [al] countries: [w1] application-area: [all] --- # Database trigger setup flags may only be set to true ## Description The `OnDatabaseInsert`, `OnDatabaseModify`, `OnDatabaseDelete`, and `OnDatabaseRename` events let one subscriber react to writes on any table, receiving the record as a `RecordRef`. They are opt-in per table through `GetDatabaseTableTriggerSetup(TableId; var OnDatabaseInsert; var OnDatabaseModify; var OnDatabaseDelete; var OnDatabaseRename)`, raised by the system codeunit `Global Triggers` (in the 2000000001..2000000010 range). Codeunit 49 `GlobalTriggerManagement` subscribes to it, collects the Dataverse integration and API webhook flags, raises its own integration event `OnAfterGetDatabaseTableTriggerSetup` with the same four `var` Booleans, and then, in the normal execution context only, adds the change log flags. That the platform raises the database events for a table only when the matching flag ends up `true` is not stated on Microsoft Learn; it is inferred from the sources below. Learn states that subscribing to global triggers disables bulk SQL insert, modify, and delete for that table, so the answer is per table. A BCApps change log test notes that global trigger management may have cached the setup for a table. The `No Transactions Subscriber` test library sets all four flags for every table so that it sees every write. The four Booleans are shared by every subscriber in the chain, and subscribers run in no particular order. A subscriber that assigns `false`, or assigns an expression that can be `false` such as `OnDatabaseModify := MySetup.Get(TableId)`, overwrites whatever another feature already set for that table if it runs after that feature. The table may then stop raising the database events, and features that rely on them (the change log, Dataverse synchronization, API webhook notifications, data archiving) stop working for it with no error. `GlobalTriggerManagement` asks the change log last, in the normal execution context only, and its comment says it does not want anyone to disable change log management. That ordering protects only the change log flags, and only against `OnAfterGetDatabaseTableTriggerSetup` subscribers. It does not protect the other features' flags, and it does not protect anything against another direct subscriber to `Global Triggers`. ## Best Practice Prefer table-specific mechanisms when the set of tables is known. Learn advises avoiding global trigger subscribers in general because every opted-in table loses bulk SQL operations. Use the database events only when the set of tables is open-ended or configurable, and turn on only the operations and tables the feature needs. Subscribe to `GlobalTriggerManagement`'s integration events, `OnAfterGetDatabaseTableTriggerSetup` to opt in and `OnAfterOnDatabaseInsert`, `OnAfterOnDatabaseModify`, `OnAfterOnDatabaseDelete`, or `OnAfterOnDatabaseRename` to react. Learn does not recommend subscribing directly to the events of system codeunits 2000000001..2000000010. Some Microsoft apps do, for example `Data Archive Db Subscriber`, `GP Collect All Modifications`, and the `No Transactions Subscriber` test library, and those subscriptions still compile and run. In the setup subscriber, only turn flags on: `if IsTracked(TableId) then OnDatabaseModify := true;`, or `OnDatabaseModify := OnDatabaseModify or IsTracked(TableId);` as `Change Log Management` does. A statement such as `if not OnDatabaseDelete then OnDatabaseDelete := false;`, which appears in BCApps, cannot clear a flag and is not this anti-pattern. In the handler, check `RecRef.Number` against the feature's own setup and skip temporary records, because the events also fire for every table another feature opted in. See sample: [`database-trigger-setup-flags-may-only-be-set-to-true.good.al`](database-trigger-setup-flags-may-only-be-set-to-true.good.al). ## Anti Pattern In a subscriber to `GetDatabaseTableTriggerSetup` (`Global Triggers`) or `OnAfterGetDatabaseTableTriggerSetup` (`GlobalTriggerManagement`), any assignment to one of the four `var` flags that can store `false` when the flag was already `true`. This includes a literal `false`, an assignment from a lookup or Boolean expression without `or` on the flag's current value, and `Clear` on the parameter. BCApps has this shape in two places, which shows the mechanism rather than an exception to it. The demo data generator assigns `OnDatabaseInsert := IsTableIDIncludedIntoFullPack(TableId)` while it collects table IDs. The test library `Backup Management` assigns all four flags from its own lookup. Both clear flags set by other features, and both run only in demo-data generation or test sessions where that is accepted. Production and extension code has no such session boundary. See sample: [`database-trigger-setup-flags-may-only-be-set-to-true.bad.al`](database-trigger-setup-flags-may-only-be-set-to-true.bad.al). ## References - [Transitioning from codeunit 1 to system codeunits](https://learn.microsoft.com/dynamics365/business-central/dev-itpro/upgrade/transition-from-codeunit1): v14-era upgrade guidance. `GetDatabaseTableTriggerSetup` and `OnDatabase*` moved to codeunit 49 `GlobalTriggerManagement`, and Learn advises against subscribing directly to system codeunits 2000000001..2000000010. - [How to refactor use of integration records to system fields](https://learn.microsoft.com/dynamics365/business-central/dev-itpro/developer/devenv-integration-record-refactoring): subscribers to codeunit 49 hurt performance, and subscribing to global triggers disables bulk SQL insert, modify, and delete for that table. - [Event types, global events](https://learn.microsoft.com/dynamics365/business-central/dev-itpro/developer/devenv-event-types#global-events): the codeunit 49 integration events. [Subscribing to events](https://learn.microsoft.com/dynamics365/business-central/dev-itpro/developer/devenv-subscribing-to-events): subscribers run one at a time in no particular order. - [GlobalTriggerManagement.Codeunit.al](https://github.com/microsoft/BCApps/blob/main/src/Layers/W1/BaseApp/GlobalTriggerManagement.Codeunit.al): the `Global Triggers` setup subscriber and its signature (lines 51-52), the change log ordering and comment in the normal execution context (62-64), `OnAfterGetDatabaseTableTriggerSetup` (173-174), and `OnAfterOnDatabase*` (178-194). - Inference sources: [ChangeLog.Codeunit.al](https://github.com/microsoft/BCApps/blob/main/src/Layers/W1/Tests/Misc/ChangeLog.Codeunit.al) line 2087 (setup cached per table) and [NoTransactionsSubscriber.Codeunit.al](https://github.com/microsoft/BCApps/blob/main/src/Apps/W1/LibraryNoTransactions/app/NoTransactionsSubscriber.Codeunit.al) lines 4-11 (all four flags on). - Only-true assignments in BCApps: `ChangeLogManagement.Codeunit.al` lines 85-88 (`or`), `APIWebhookNotificationMgt.Codeunit.al` 224-227, `CRMIntegrationManagement.Codeunit.al` 3748-3753, `MasterDataManagement.Codeunit.al` 1511-1516, `DataArchiveDbSubscriber.Codeunit.al` 27-32, and `GPCollectAllModifications.codeunit.al` 11-21. - Flag-clearing assignments in demo and test code: [CreateDemonstrationData.Codeunit.al](https://github.com/microsoft/BCApps/blob/main/src/Layers/W1/DemoTool/CreateDemonstrationData.Codeunit.al) lines 343-344 (also the CZ layer line 353 and the IN layer line 357) and [BackupManagement.Codeunit.al](https://github.com/microsoft/BCApps/blob/main/src/Layers/W1/Tests/TestLibraries/BackupManagement.Codeunit.al) lines 470-476.