---
id: change/bcquality/133
type: change
title: "#133 Add TransferFields SkipFieldsNotMatchingType guidance"
summary: Added guidance in BCQuality to warn developers against using TransferFields with SkipFieldsNotMatchingType as a blanket solution, as it can silently drop fields when type mismatches occur within the same extension.
tier: official
language: en
tags:
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  - main
system: development
review:
  state: reviewed
  by: opus
  at: "2026-10-08T02:07:55.565Z"
  flags: []
generated:
  at: "2026-10-08T01:26:53.141Z"
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  input_hash: 9fab60153f868536e63c9d62626293197288ac94
evidence:
  - kind: code
    url: https://github.com/microsoft/BCQuality/pull/133
    title: "microsoft/BCQuality#133: Add TransferFields SkipFieldsNotMatchingType guidance"
    date: "2026-08-24"
    commit: 9fab60153f868536e63c9d62626293197288ac94
    t: null
    quote: null
links:
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number: 133
repo: microsoft/BCQuality
source_id: bcquality-prs
url: https://github.com/microsoft/BCQuality/pull/133
kind: pr
base_branch: main
major: null
merged_at: "2026-08-24T07:54:37Z"
author: yahyatouil-dev
author_type: User
community_contribution: false
labels: []
change_class: code
change_kind: other
behavior_change: false
breaking: false
files:
  count: 3
  additions: 140
  deletions: 0
  al: 3
apps: []
objects_touched: []
objects_unjoined:
  - path: community/knowledge/data-modeling/transferfields-skip-type-mismatch-can-drop-data.bad.al
    status: added
    reason: not-in-snapshot
  - path: community/knowledge/data-modeling/transferfields-skip-type-mismatch-can-drop-data.good.al
    status: added
    reason: not-in-snapshot
  - path: community/knowledge/data-modeling/transferfields-skip-type-mismatch-can-drop-data.md
    status: added
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obsoletions: []
backports: []
fixes_issues: []
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systems:
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joined_against:
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  commit: null
---

# #133 Add TransferFields SkipFieldsNotMatchingType guidance

> Added guidance in BCQuality to warn developers against using TransferFields with SkipFieldsNotMatchingType as a blanket solution, as it can silently drop fields when type mismatches occur within the same extension.

[Pull request](https://github.com/microsoft/BCQuality/pull/133) · merged into `main` on 2026-08-24 by yahyatouil-dev · 3 files (+140 -0), 3 AL · other · tier official · reviewed (checked by Opus)

## What changed

- New knowledge rule explains that TransferFields only errors on type mismatches within the same extension, not cross-extension
- Using SkipFieldsNotMatchingType to suppress errors can mask silent field drops
- Good pattern: use explicit field-by-field mapping with Evaluate for type conversions to fail loudly
- Bad pattern: relying on SkipFieldsNotMatchingType when destination needs all source fields copied
- Rule includes code examples and verification against Microsoft Learn documentation

## AL objects touched

- `community/knowledge/data-modeling/transferfields-skip-type-mismatch-can-drop-data.bad.al`: added, not in the BC? snapshot yet
- `community/knowledge/data-modeling/transferfields-skip-type-mismatch-can-drop-data.good.al`: added, not in the BC? snapshot yet
- `community/knowledge/data-modeling/transferfields-skip-type-mismatch-can-drop-data.md`: added, not in the BC? snapshot yet

## Context

- Systems: development

Source: metadata of a merged pull request in microsoft/BCQuality (bcquality): title, labels, changed paths and counts, with a summary in our words. No source text and no description beyond one short quote (D10, D61).