bcquality/microsoft/knowledge/data-modeling/delete-master-data-with-trigger.md

bc-version	domain	keywords	technologies	countries	application-area
all	data-modeling	delete deleteall runtrigger ondelete master-data currency cleanup data-migration	al	w1	all

Delete master and reference data with Delete(true) so the owning table's OnDelete decides

Description

Record.Delete() and Record.DeleteAll() do not run OnDelete unless RunTrigger is true; the default is false. On a master or reference table, OnDelete is where Business Central decides whether the delete is safe and removes what the record owns. Currency.OnDelete refuses the delete while any open customer, vendor, or employee ledger entry uses the code, then deletes the currency's Currency Exchange Rate rows itself. Customer.OnDelete refuses when a job bills the customer, calls codeunit 361 MoveEntries (which refuses while ledger entries fall in an unclosed fiscal year or are still open, and otherwise detaches the closed history), and removes default dimensions, related data, and the contact link.

A cleanup, migration, or "remove obsolete codes" routine that calls Delete()/DeleteAll() without true on such a table skips all of it (only OnBeforeDelete/OnAfterDelete triggers in table extensions still run): it can remove a currency that open entries still use, and leaves exchange rates and other dependents orphaned. That a record looks obsolete — a superseded currency nobody posts in any more — is no evidence the guard would pass, and keeping a record that closed history still refers to is often the better choice. Where the master has a Blocked field, blocking it is an alternative to deleting it; Currency has none.

Best Practice

Outside the owning table's own triggers, delete master and reference records with Delete(true)/DeleteAll(true) and let OnDelete raise its error, as BCApps does when it removes items (CatalogItemManagement, NewItem.Delete(true)). This is the "trigger does work the caller depends on" case of pass-false-to-insert-when-trigger-not-needed; a hand-written reference check is no substitute for the guard.

Legitimate false deletes, not in scope: the owning table's own OnDelete cascade removing its dependents (Currency.OnDelete itself calls CurrExchRate.DeleteAll(); see owning-table-must-delete-dependents-in-ondelete); temporary records and buffers; deleting and immediately re-inserting the same primary key to restore or recreate a record, where dependents stay valid (JobArchiveManagement restoring a project from its archive; codeunit 1812 recreating each "Customer Posting Group" with the same Code); and a data-migration or setup reset in a company with no posted entries that removes master rows and their setup references as one rebuild, such as codeunit 1812 "Data Migration Del G/L Account", whose DeleteAll() bypasses "G/L Account".OnDelete's MoveGLEntries guard — acceptable only because no postings exist yet. Posted ledger entries are not master data; see do-not-modify-or-delete-posted-ledger-entries.

See sample: delete-master-data-with-trigger.good.al.

Anti Pattern

Code outside the owning table's OnDelete calls Delete()/DeleteAll() (or false) on a non-temporary master or reference table — Currency, Customer, Vendor, Item, G/L Account, or a custom equivalent with an OnDelete guard or cascade — typically from a filter on codes judged obsolete, outside a same-key delete-and-reinsert or a no-postings migration/setup rebuild.

See sample: delete-master-data-with-trigger.bad.al.

References

• Record.Delete method and Record.DeleteAll method: RunTrigger "The default value is false."; the DeleteAll note adds that setting it to false "only affects the OnDelete trigger" — table-extension OnBeforeDelete/OnAfterDelete still run.
• BCApps src/Layers/W1/BaseApp/Finance/Currency/Currency.Table.al, OnDelete, lines 797-820.
• BCApps src/Layers/W1/BaseApp/Sales/Customer/Customer.Table.al, OnDelete, lines 2401-2430; src/Layers/W1/BaseApp/Utilities/MoveEntries.Codeunit.al, MoveCustEntries, lines 126-167.
• BCApps src/Layers/W1/BaseApp/Inventory/Item/Catalog/CatalogItemManagement.Codeunit.al, line 419.
• BCApps src/Layers/W1/BaseApp/System/DataMigration/DataMigrationDelGLAccount.Codeunit.al, OnRun lines 18-32 and DeleteGLAccounts lines 34-42 (rebuild); lines 53-56 (same-key delete and re-insert); src/Layers/W1/BaseApp/Finance/GeneralLedger/Account/GLAccount.Table.al, OnDelete, line 1144 (MoveGLEntries).
• BCApps src/Layers/W1/BaseApp/Projects/Project/Archive/JobArchiveManagement.Codeunit.al, lines 212-219 (restore: Job.Delete(), then re-insert the same No.).