Database theory

Geospatial data is commonly stored in some databases and typically a database that adheres to the Relational Database model. Where data is stored in relations (labels) and where each feature is one row and each attribute one column

The relational database model typically supports a processing language named Structured Query Language (SQL) tjay allows for the manipulation of the database. In most cases you only need, to understand a subset of SQL, namely how to filter data and how to join data.

Filtering data using SQL