bcquality/microsoft/knowledge/performance/avoid-findfirst-with-next.md
Jesper Schulz-Wedde 32c40bbf1d Seed performance knowledge corpus (22 articles + AL samples)
Converts an existing performance-review prompt into 22 atomic
knowledge articles under microsoft/knowledge/performance/, each
paired with AL samples under samples/performance/<slug>/ demonstrating
the anti-pattern and/or the best practice. The full set seeds the
corpus the microsoft/skills/al-performance-review leaf skill matches
against and validates the READ knowledge-file format end-to-end.

Every article conforms to the READ contract: six required frontmatter
fields, Description always present, no fenced code blocks, sample
code referenced by repo-relative path. Each article is marked with a
blockquote 'Seed article' note so domain stewards can extend or
restructure them freely.

Articles (ordered by concern area):

Database query efficiency
- use-findset-with-next (AA0181)
- avoid-findfirst-with-next (AA0233)
- only-fetch-records-you-use (AA0175)
- use-findset-readonly-by-default
- use-setloadfields-for-partial-records
- use-addloadfields-in-report-layouts
- use-calcsums-to-aggregate-filtered-sets (file: use-calcsums-for-flowfield-totals.md)
- avoid-calcfields-in-loops
- add-sift-keys-for-flowfields (AA0232)
- use-isempty-for-existence-checks

Filter and key optimization
- filter-before-find
- set-current-key-to-match-filters

Temporary tables and transactions
- use-temporary-tables-for-intermediate-data
- keep-transaction-scope-short
- avoid-user-interaction-in-transactions
- avoid-commit-inside-loops

Record operations
- prefer-get-for-primary-key-lookups
- use-insert-false-when-skipping-triggers
- prefer-direct-record-over-recordref

Strings, codeunits, events
- use-strsubstno-for-message-formatting
- use-single-instance-codeunits-for-caching
- keep-event-subscribers-lightweight

samples/README.md documents the sample-folder convention and makes
clear the samples are demonstration-only, not derived from BC base
application source, with unique object IDs in the 50100-50199 range.

Rubber-duck pass caught: a misleading good.al in avoid-calcfields-in-loops
(fixed by switching to a hoistable CalcFields scenario), an invalid
event subscriber signature in keep-event-subscribers-lightweight
(fixed by adding var xRec), normative guidance leaked into the
Description of use-findset-readonly-by-default (moved to Anti Pattern),
a missing sample pair for keep-transaction-scope-short (added), and
muddy FlowField/CalcSums framing (retitled and clarified).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-17 13:23:34 +02:00

1.2 KiB

bc-version domain keywords technologies countries application-area
26..28
performance
findfirst
findlast
get
next
aa0233
al
w1
all

Do not pair FindFirst, FindLast, or Get with Next

Seed article. Converted from an existing performance-review prompt to bootstrap the BCQuality performance corpus. Domain stewards should expand, restructure, and refine as needed.

Description

CodeCop rule AA0233 flags loops that start with FindFirst, FindLast, or Get and then call Next. FindFirst and FindLast retrieve a single row and reposition the cursor; calling Next after them forces the platform to re-seek and stream the rest of the set, which is slower than the correct FindSet pattern and signals intent incorrectly to reviewers and the optimizer.

Best Practice

Choose the Find variant that matches the operation: FindSet for full iteration, FindFirst or FindLast when you want exactly one row, Get when the primary key is known. Never call Next after FindFirst, FindLast, or Get.

Anti Pattern

Writing if Rec.FindFirst() then repeat ... until Rec.Next() = 0 is the canonical AA0233 offender. The loop wastes bandwidth and obscures the author's intent.

See sample: samples/performance/avoid-findfirst-with-next/bad.al.