| bc-version |
domain |
keywords |
technologies |
countries |
application-area |
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performance |
| isempty |
| count |
| findfirst |
| existence-check |
| exists |
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Use IsEmpty for existence checks, not Count() or FindFirst()
Description
When the caller only needs to know whether any row matches a filter, IsEmpty() is the API designed for the question. Per the upstream guidance, "IsEmpty() is more efficient as it stops at first record found." Count() > 0 materializes a count the caller does not need; FindFirst() materializes a row the caller does not need. Both do work that IsEmpty does not.
Best Practice
Phrase existence checks as if not Record.IsEmpty() then ... (or if Record.IsEmpty() then ... for the negative). Apply filters via SetRange/SetFilter before the call so the existence check runs against the intended subset. Reserve Count for cases where the actual number matters and FindFirst for cases where the record fields are read.
See sample: use-isempty-for-existence-check.good.al.
Anti Pattern
if Customer.Count() > 0 then ... and if Customer.FindFirst() then ... (when the record is discarded) — both are flagged by the upstream guidance as the wrong tool. The first asks the database for the full count; the second asks for a row's fields. Both answers go unused.
See sample: use-isempty-for-existence-check.bad.al.
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