bcquality/microsoft/knowledge/security/validatetablerelation-false-on-user-input.md
Jesper Schulz-Wedde a9f3c50863 Regenerate microsoft/knowledge from upstream BCApps instructions
The previous LLM-generated knowledge files contained factual
hallucinations. The most visible was the claim that `FindFirst` /
`FindLast` "forces a full-table scan" on an unfiltered record - it does
not; those APIs return a single row via the current key.

Other inaccuracies the audit found and fixed:

* `FindSet(true)` was described as "taking a LockTable". The correct
  upstream phrasing is that `FindSet(true)` sets
  `ReadIsolation::UpdLock` on the read. UpdLock and LockTable are
  related but distinct mechanisms.
* The list of production-scale tables had been invented beyond the
  upstream source (e.g. "Detailed Cust. Ledg. Entry") without a
  citation. The regenerated list matches the ten tables upstream lists
  with their P95 row counts.
* `SetLoadFields` guidance had been augmented with an extra mechanism
  claim ("the database resolves the filter using the index without
  hydrating the value") not present in upstream.

Approach: full regeneration of `microsoft/knowledge/` from the six
upstream BCApps Code Review instruction files, with Microsoft Learn /
the AL language reference as a secondary source. Every claim in every
regenerated file is anchored to a verbatim upstream quote (or a Learn
URL); the audit trail lives in artifacts/trace-<domain>.json on the
session workspace.

The PR #11 transaction/error-handling cluster is preserved verbatim:

* performance/understand-implicit-transaction-boundary.md
* performance/codeunit-run-as-atomic-sub-operation.{md,good.al,bad.al}
* performance/codeunit-run-requires-prior-commit-inside-transaction.{md,good.al,bad.al}
* performance/use-tryfunction-for-error-catching-not-rollback.{md,good.al,bad.al}
* performance/avoid-commit-inside-loops.{md,good.al,bad.al}
* security/commitbehavior-attribute-scopes-explicit-commits.{md,good.al,bad.al}
* testing/transactionmodel-attribute-governs-test-transactions.{md,good.al,bad.al}

These articles already cite Microsoft Learn and were carefully
cross-referenced; the regeneration skips their topics rather than
duplicating them.

File counts after regeneration:

  performance   35 .md  (5 preserved + 30 new)
  privacy       17 .md
  security      18 .md  (1 preserved + 17 new)
  style         33 .md
  testing        1 .md  (preserved)
  ui            19 .md
  upgrade       18 .md

Total 141 atomic knowledge files, each strictly one rule. All pass
.github/scripts/validate_frontmatter.py with 0 errors and 0 warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-21 09:53:09 +02:00

1.9 KiB

bc-version domain keywords technologies countries application-area
all
security
validatetablerelation
tablerelation
field
validation
input
al
w1
all

Do not set ValidateTableRelation = false on user-editable fields

Description

TableRelation on a field declares that the field's value must exist in another table; the platform validates the value on entry and on Validate. Setting ValidateTableRelation = false keeps the relation as metadata (used by lookups, by Edit-in-Excel, by APIs) but turns off the runtime check. On a system-controlled, non-editable field that is populated only by the platform or by a posting routine, that is acceptable. On a user-editable field, it is dangerous: users can type any value, and downstream code that assumes the relation holds will read a Customer record that does not exist, post to an account that was deleted, or join against missing rows.

Best Practice

Leave ValidateTableRelation at its default (true) on any field a user can edit. If there is a legitimate reason to turn it off — typically because the relation is not on the primary key, or because the relation is computed — replace it with an OnValidate trigger that performs the equivalent check (if FieldValue <> '' then VerifyExternalReferenceExists(FieldValue)). Combine ValidateTableRelation = false with Editable = false for system-controlled fields, so the metadata is correct and the field is unreachable from the UI. See sample: validatetablerelation-false-on-user-input.good.al.

Anti Pattern

ValidateTableRelation = false on a user-facing input field (a Customer No. typed by a sales user) with no alternative validation. Reviewers should flag the combination of ValidateTableRelation = false and any of: Editable = true (the default), an OnValidate trigger that does not perform the relation check, or a page that surfaces the field as input. See sample: validatetablerelation-false-on-user-input.bad.al.