bcquality/microsoft/knowledge/testing/tablerelation-requires-prerequisite-records.md

bc-version	domain	keywords	technologies	countries	application-area
all	testing	tablerelation prerequisite validate foreign-key test-data	al	w1	all

Create related records before inserting test data that points to them

Description

A field with a TableRelation is checked when you Validate it or call Insert(true): the platform confirms the referenced parent record exists. Test data assembled bottom-up — a sales line before its item, a ledger entry before its account — fails this check with a relation error, again a runtime abort rather than an assertion. Order matters: every record a foreign key points to must already exist when the dependent record is validated or inserted. The fix is to build fixtures top-down, parent before child, so each TableRelation resolves.

Best Practice

Create prerequisite records first, then reference their primary keys from dependent records. Use the test Library codeunits, which create valid parents that satisfy mandatory fields and number series: LibraryInventory.CreateItem before a sales line that points at it, LibrarySales.CreateCustomer before a sales header. Validate the foreign-key field so the relation — and any field-validation logic — runs exactly as it would in production.

See sample: tablerelation-requires-prerequisite-records.good.al.

Anti Pattern

Assigning an invented foreign key — SalesLine."No." := 'GHOST' — and calling Insert(true) (or Validate) without creating the parent. The TableRelation check rejects the row, the test aborts before its assertions, and the failure reads as a data error instead of the missing-setup bug it is.

See sample: tablerelation-requires-prerequisite-records.bad.al.