ebceff2332
These articles capture BC-specific mechanics agents still invert: partial-record JIT on writes, Reset clearing SetLoadFields, HttpClient inside write transactions, and batched number series, plus negative guidance that stops over-eager Query and IsEmpty "fixes". Co-authored-by: Cursor <cursoragent@cursor.com>
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IsEmpty immediately before FindSet is an extra round-trip
Contributions welcome — open a PR to refine or extend this article.
Description
IsEmpty is the right API when the caller only needs existence — see microsoft/knowledge/performance/use-isempty-for-existence-check.md. It is not a cheap guard in front of a loop that will FindSet anyway. Both calls hit the database; FindSet already returns false when the filter matches nothing. Agents and reviewers often insert if not Rec.IsEmpty() then "for performance" and pay a second query for a result the iterator already provides.
Best Practice
When the body iterates, open with if Rec.FindSet() then repeat ... until Next() = 0. Do not flag a bare FindSet loop as missing an IsEmpty precondition. Reserve IsEmpty for branches that never materialize the row set.
See sample: isempty-before-findset-is-extra-round-trip.good.al.
Anti Pattern
if not Rec.IsEmpty() then if Rec.FindSet() then repeat. Also a false-positive review comment that asks to add that guard. The second read does not avoid the first; it duplicates it.
See sample: isempty-before-findset-is-extra-round-trip.bad.al.