When doing a sub-query with an "or" sub-query join, records with an entry in the specified table that meets at least one of the conditions will be returned. This is very similar to using a standard query "or" join. One difference is that since the sub-query is calculated as a single unit, it will generally yield results faster than doing separate query statements. The other two differences relate to aggregates and counts, as discussed below.
Using the "or" sub-query join, the two individuals in the previous example WOULD be returned, because they meet at least one of the specified conditions.
Article ID: 753
Last updated: 07 Mar, 2010