The Related Records Table widget allows you to embed a table of data from an ArcGIS feature service into your report, either by following the relationships defined in your master feature service or by using a geographical query.
Relationships in ArcGIS Server/Online allow you to query data from one table or service based on a relationship defined in your source or master service. So, for example, by using relationships you can specify that your Wards service is related to your Districts service based on a lookup in a field in your Wards. Or you could have a relationship going the other way – for your Districts service you could use relationships to link to all the Schools that lie within each district feature. Report Builder can use these relationships to query data and embed it in your report. An InstantAtlas Data Catalog also makes use of these relationships to make it easy for you to use comparison data in your reports.
Using a Geographical Query
If your feature services do not have explicit relationships defined, the Related Records Table widget can also find related records from another feature service using a geographical query – for example, “find all schools that lie within this district”.