📋✅ Attribute Table in QGIS: Viewing and Editing Data

🟢 What is the Attribute Table?

The Attribute Table in QGIS stores all the non-spatial data (e.g., name, ID, population) attached to each spatial feature (point, line, or polygon).
Each row = one feature, and each column = one attribute field.

✅ Step-by-Step: View the Attribute Table

🔹 Step 1: Load or Create a Layer

• Add a vector layer (shapefile, GeoPackage, etc.) to your project.

🔹 Step 2: Open Attribute Table

• Right-click on the layer name → Open Attribute Table
  or select the layer and click the Attribute Table icon (📋)

🟢 Attribute Table Interface Overview

✏️ Editing Attribute Data

✅ Step 1: Toggle Editing Mode

• Click ✏️ Toggle Editing on the top-left of the table.

✅ Step 2: Make Changes

You can now:

• Edit cell values directly (like in Excel)

• Add new rows (if geometry is also added)

• Delete rows (select row → click delete)

✅ Step 3: Save Changes

• Click 💾 Save Edits after editing

• Then click ✏️ Toggle Editing again to stop editing mode

🧮 Using the Field Calculator

The Field Calculator is powerful for:

• Creating new fields

• Updating existing fields

• Calculating values (e.g., area, population density)

Example: Add an Area Field

1. Open Attribute Table → Click Field Calculator

2. Check ✅ Create a new field

   • Name: Area_km2

   • Output type: Decimal number (real)

3. Expression:

   $area / 1000000


   (converts square meters to square kilometers)

4. Click OK

🔍 Filtering and Sorting Data

• Use Filter (Funnel icon) to display only matching records

Use Expression Filter for advanced queries like:

"Population" > 1000 AND "District" = 'Cuttack'

• Click on column headers to sort ascending/descending

📌 Pro Tips

• Use the “Form View” tab (top-right) for single record editing

• Join external data (e.g., CSV) to add more attributes

• Export attribute table as CSV:

  Right-click layer → Export → Save Features As → Format: CSV