bcquality/microsoft/knowledge/performance/load-common-fields-before-branching-on-case.md
Jesper Schulz-Wedde 2b5550c346
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Improve partner onboarding and documentation navigation (#174)
Lead with a complete plugin quick start and add task-oriented usage, troubleshooting, customization, and contribution guides. Preserve the broader plugin framing, correct conflicting contract guidance, support Agents folder reviews, and align repository validation. Convert existing sample references to clickable links without changing knowledge rules.

Co-authored-by: Jesper Schulz-Wedde <jesper.schulzwedde@microsoft.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
2026-09-09 17:31:03 +02:00

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---
bc-version: [all]
domain: performance
keywords: [setloadfields, case, conditional, branch, field-loading]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Load common fields before branching on case
> Contributions welcome — open a PR to refine or extend this article.
## Description
When a known input determines which fields a subsequent record read will use, a single `SetLoadFields` containing every branch's fields loads unnecessary columns. Build the selection before `Get`, `FindFirst`, or `FindSet`: use `SetLoadFields` for fields common to every branch, then `AddLoadFields` for the selected branch. `SetLoadFields` replaces the current selection, while `AddLoadFields` preserves it.
## Best Practice
Call `SetLoadFields` with the common fields. In each branch, call `AddLoadFields` with that branch's normal fields and then perform the record read. This applies only when the discriminator is known before the read; branching on a field from an already-loaded row is too late to tailor that row's initial SQL projection.
See sample: [`load-common-fields-before-branching-on-case.good.al`](load-common-fields-before-branching-on-case.good.al).
## Anti Pattern
A single top-level `SetLoadFields` enumerating every branch's fields, or a branch-local `SetLoadFields` that accidentally discards the common selection. Both make the declared load plan differ from the fields the selected path actually uses.
See sample: [`load-common-fields-before-branching-on-case.bad.al`](load-common-fields-before-branching-on-case.bad.al).