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3-Minute Quick Start

Get your first filter working in just 3 minutes!

What You'll Learn
  • How to open FilterMate
  • How to apply an attribute filter
  • How to see results on the map

Time: ⏱️ 3 minutes
Difficulty: ⭐ Absolute Beginner
Prerequisites: QGIS installed + any vector layer loaded

The Goal​

Filter a cities layer to show only large cities (population > 100,000)

Step 1: Open FilterMate (30 seconds)​

  1. Look for the FilterMate icon in your QGIS toolbar:

    FilterMate icon

  2. Click it, or go to Vector → FilterMate

  3. The FilterMate panel appears (usually on the right side)

Panel Position

You can drag the panel to any edge of your QGIS window, or make it floating.

Step 2: Select Your Layer (30 seconds)​

In the Layer Selection dropdown at the top of the FilterMate panel:

  1. Click the dropdown
  2. Choose your cities/municipalities layer
  3. FilterMate analyzes the layer and shows:
    • Backend type (PostgreSQL⚡ / Spatialite / OGR)
    • Feature count (e.g., "450 features")
    • Available fields

Don't have a cities layer?

  • Use any layer with a numeric field
  • Or download our sample dataset (5 MB)

Step 3: Write a Filter Expression (1 minute)​

Now let's filter to show only features where population is greater than 100,000.

Find the Expression Box​

In the FilterMate panel, look for the expression builder - it's the text input area in the FILTERING or EXPLORING tab.

Type Your Expression​

"population" > 100000
Field Names
  • Field names are case-sensitive
  • Use double quotes around field names: "population"
  • Use single quotes for text values: 'Paris'

Alternative Expressions (adapt to your data):

For a layer with different field names
-- If your field is called "POPULATION" (uppercase)
"POPULATION" > 100000

-- If your field is called "pop" or "habitants"
"pop" > 100000
"habitants" > 100000

-- Multiple conditions
"population" > 100000 AND "country" = 'France'

Step 4: Apply the Filter (30 seconds)​

  1. Look for the Apply Filter button (usually has a funnel icon 🔽)
  2. Click it
  3. Watch the magic happen! ✨

What you should see:

  • The map updates to show only filtered features
  • The feature count updates (e.g., "Showing 42 of 450 features")
  • Filtered features are highlighted on the map

✅ Success! What Just Happened?​

FilterMate applied your expression to every feature in the layer:

  • Features with population > 100000: ✅ Shown
  • Features with population ≤ 100000: ❌ Hidden

The original data is unchanged - FilterMate creates a temporary filtered view.

🎓 What's Next?​

Learn More Filtering Techniques​

Geometric Filtering (10 min)
Find features based on location and spatial relationships
▶️ Your First Geometric Filter

Export Your Results (5 min)
Save filtered features to GeoPackage, Shapefile, or PostGIS
▶️ Export Guide

Undo/Redo (3 min)
Navigate your filter history with intelligent undo/redo
▶️ Filter History

Explore Real-World Workflows​

Urban Planning (10 min)
Find properties near transit stations
▶️ Transit-Oriented Development

Real Estate (8 min)
Multi-criteria property filtering
▶️ Market Analysis

🆘 Troubleshooting​

"No features match"​

Possible causes:

  1. Expression syntax error - Check for typos
  2. Field name incorrect - Right-click layer → Open Attribute Table to verify field names
  3. Threshold too high - Try a lower value: "population" > 10000

Quick fix:

-- Try this simpler expression first
"population" IS NOT NULL

This should show all features with a population value.

"Field not found" error​

Cause: Field name doesn't match exactly

Solution:

  1. Right-click your layer → Open Attribute Table
  2. Find the column with population data
  3. Note the exact field name (including capitalization)
  4. Use that exact name in quotes: "YourFieldName"

Can't find the Apply button​

The Apply Filter button location depends on your configuration:

  • Bottom of panel (default)
  • Top near layer selector
  • Left or right side (if configured)

Look for a button with a funnel icon (🔽) or the text "Apply Filter".

💡 Pro Tips​

1. Use the Field List​

Most FilterMate interfaces show a list of available fields. Click a field name to insert it into your expression automatically.

2. Check Expression Validity​

FilterMate validates your expression in real-time:

  • ✅ Green checkmark = Valid
  • ❌ Red X = Syntax error (hover for details)

3. Combine with Map Selection​

You can combine FilterMate filters with QGIS's manual selection tool:

  1. Apply FilterMate filter
  2. Use Select tool to refine further
  3. Only filtered features are selectable

🎉 Congratulations!​

You've successfully applied your first filter! You're now ready to explore FilterMate's more advanced features.

Continue Learning:

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