Master-Detail Relation Editor

When a data source contains two or more queries, clicking the button in the Field List will invoke the Master-Detail Relation Editor.

Using this editor, you can define master-detail relationships between queries by specifying their corresponding key fields.

This allows you to create hierarchical data sources that are used to create nested master-detail reports.md).

[!NOTE] Although it is also possible to join different tables within a single query, creating hierarchical data sources is preferred in most cases to provide better performance (in general, master-detail reports are generated faster than similar-looking reports created by grouping "flat" data sources).