GeneXus provides a GXquery API that allows developers to handle data types and methods to integrate queries made through GXquery within a GeneXus application.
To know about which are the initial settings and how the tool must be used in a few steps, follow this link: HowTo: Preparing and Using the GXquery API
The purpose of the following links is to describe the different objects, enumerating each one of their properties and methods. Follows the complete list of the data types that provide these properties and methods.