Select by Attributes & Field Calculator

Описание: Got it 👍 Let’s go step by step. Both Select by Attributes and the Field Calculator are powerful tools in ArcGIS (ArcMap and ArcGIS Pro).

🔹 1. Select by Attributes

This tool lets you select features in a layer using a SQL query.

How to use:

Right-click the layer → Selection → Select by Attributes.

Choose the layer and method (e.g., New selection, Add to selection).

Build an expression using the field names, operators, and values.

🔹 2. Field Calculator

Used to update or calculate values in an attribute field (numeric, text, date, etc.).

How to use:

Open the attribute table → right-click the field → Field Calculator.

Choose the Parser:

VB Script (older ArcMap)

Python (recommended in ArcMap & ArcGIS Pro)

Enter an expression.

Examples:

Text field:

🔹 Combine Both

Often, you use Select by Attributes first, then apply the Field Calculator only to the selected records.

👉 Example workflow:

Select by Attributes: