Value Relation search matches all columns instead of display column only — affects feature form and filter widgets

[RastoHu]

Description

When searching in a Value Relation widget (both in a feature form and in a Single/Multi select filter), the search matches against all columns of the referenced table instead of only the configured display column. This causes unexpected results — for example, searching for "Bratislava" returns "Slovakia" because "Bratislava" appears in another column (capital city) of the world_capitals lookup table, even though the display column is country.

Affects:

• Feature form — Country field (Value Relation widget) when adding/editing a feature
• Filter page — Multi select-POI-Country (and any Single/Multi select filter backed by a Value Relation)

Environment

• PROD

Application (+ app version, build, operating system)
Mergin Maps iOS 2026.2.0 / iOS 26.4

Steps to reproduce

Feature form:

1. Open project tester-ws-1/preview_mode_bug
2. Add a new feature in the POI layer → open the feature form
3. Tap the Country field (Value Relation widget referencing world_capitals, display column = country)
4. Type "Bratislava" in the search field

Filter:

1. Open Filters → Multi select-POI-Country
2. Type "Bratislava" in the search field

Actual results

• "Slovakia" is returned as a match for "Bratislava" — the search matched a non-display column (capital city name) in the world_capitals table
• Other non-display columns also produce unexpected matches

Expected results

• Search should only match against the configured display column (country)
• Searching "Bratislava" should return no results since no country is named "Bratislava"

Screenshots or logs

ScreenRecording_05-19-2026.13-11-26_1.mov

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Conclusion
Created by Claude and supervised by a human test analyst.