Query Builder

The query builder allows you to create provider specific filter expressions. These are usually evaluated much faster than the generic QGIS expressions, but are sometimes limited (e.g. for shape files) or behave diffently.

Providers

Provider	Documentation
OGR	where clauses depending on the format (eg. OGR SQL for shape files)
PostgreSQL/PostGIS	where clauses using PostgreSQL and PostGIS
SpatiaLite	where clauses using SQLite and SpatiaLite
Oracle Spatial/Locator	where clauses using Oracle Spatial/Locator
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