Select rows with no data values in a joined field using ArcMap

Summary

When data is joined in ArcMap using the default 'Keep all records' option some rows may have no data values. This occurs when a row in the destination table doesn't have a matching row in the source table.

Procedure

1. Start ArcMap.
2. Click Selection > Select By Attributes.
3. Create a query that searches for null values in the joined field and includes fields from more than one table in the join. For example, if tableB is joined to FeatureClassA, the following query will return null values:
   
   

   
   tableB.fieldB is Null and FeatureClassA.OBJECTID is Not Null

   
   
   

   Note:
   Because the OBJECTID field does not allow Nulls, the 'FeatureClassA.OBJECTID is Not Null' part of the query will return True for all rows.