Aller au contenu principal

Select by Attributes

Overview

The Select by Attributes tool filters features by attribute conditions and outputs matching features as a new feature dataset. Conditional expressions support common SQL operators and pandas query syntax.

Use Cases

  • Data filtering: Select features that meet a specific threshold or category condition, such as population > 1000000.
  • Data cleaning: Quickly locate features with null values, outliers, or specific codes.
  • Thematic map preparation: Export features with a specific attribute as an independent layer for symbolization.

Parameters

ParameterDescriptionNotes
Input featuresThe feature dataset to filter by attributes.Supports point, line, polygon, and other feature types.
Query conditionThe logical expression used for filtering.Supports common SQL logical operators.
Output feature datasetThe output filtering result.Supports common vector formats.

Steps

  1. Start the tool: Open the Geoprocessing Toolbox > go to Vector Tools > Feature Processing > Select > start the Select by Attributes tool pane.
  2. Set the input: Select Input features.
  3. Configure parameters: Build a logical expression in Query condition.
  4. Configure the output: Set the output path and file name.
  5. Run and generate: Click Run and review the result.

Notes

  • For string matching, single quotation marks are recommended, for example Type == 'Residential'.
  • Because of precision issues in floating-point comparison, range conditions are recommended, such as area > 9.9 and area < 10.1.
  • Make sure field names are spelled exactly as they appear in the expression.