Membership Checks

At a Glance

This reference page walks you through the Membership Checks category of query keywords available in Altium Designer for PCB and PCB Library documents, showing what each keyword does, how to write the syntax correctly, and what kinds of objects each query returns. It covers unit conversion functions such as AsMils and AsMM, along with object and property matching functions like ComponentInLayerClass, ExistsOnLayer, HasFootprint, HasFootprintPad, HasMaskExpansionOnLayer, HasPad, and HasViaFeature, using clear examples and important notes such as required quote usage and specific query behaviors. If you want a quicker way to understand how these query keywords work and how to apply them accurately in your own filters, this page gives you a practical, example-driven starting point, keep reading to sharpen your PCB query skills.

- You will learn which Membership Checks query keywords are available in Altium Designer and what each one is used for.
- You will see the correct syntax and example queries for selecting objects by units, layers, footprints, pads, mask expansion, and via features.
- You will pick up important usage notes, including required single quotes and software-specific behavior that can affect query results.
Go Deeper with AI:

The Membership Checks PCB query functions shown in the Query Helper dialog
The Membership Checks PCB query functions shown in the Query Helper dialog

This reference page details the query language keywords from the Membership Checks category available in PCB and PCB Library documents in Altium Designer. For help on a specific query keyword, use the following collapsible sections or highlight (or click inside) any given keyword in the Query Helper or a Filter panel, then press F1 to access its section immediately.

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Contents
Feature Availability

The features available to you depend on which Altium solution you have – Altium Develop, Altium Agile Teams, Altium Agile Enterprise, or Altium Designer (on active term).

If you don’t see a documented feature in your actual software, contact Altium Sales to find out more.

Legacy Documentation

Altium Designer documentation is no longer versioned. If you need to access documentation for older versions of Altium Designer, visit the Legacy Documentation section of the Other Installers page.