Using ArcMap 10.1. Is this possible to have one polygon and join to a database/excel with many matching records? I would like to have 1 polygon but match to 100 corresponding records in a table. When I use the identify tool or select this polygon all 100 matching records would display?
MakeQueryTable will perform a one-to-many join from polygon to a table. It only works on a geodatabase, no shapefile support. Also, your excel/database table must be copied to the same workspace as the polygon features. The tool output is a feature layer, so you will want to save to disk with Copyfeatures.
I'm not sure that you can actually do a many to one join within a polygon. And, once you did I"m not sure exactly what you could calculate or do with it. But, a relate will link the polygon to your excel file and should make it so the records can be pulled up from the polygon. Here's esri's documentation on it from 9.3: http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=relating_tables