Take the datatable created from the spreadsheet and add it to your solution using the ORM. The added table may or may not have the same datasource as the table that is the source for your EntityList
You could now, of course, just compare each row in the table generated from the spreadsheet with each object in your EntityList, but here is something that is a little fancier.
Create a new PersistenceManager and import your EntityList into the PM's cache.
For each row in the spreadsheet table:
(1) If there could be duplicate rows between the two tables, search the new PM's cache for the row in the spreadsheet table with the 3 matching columns. Be sure to use a QueryStrategy of CacheOnly. If you find a match, it's a duplicate. Ignore that row.
(2) If the row is not a duplicate, create a new row (i.e., object), copy the values from the three columns, and add the new object to your EntityList.
Edited by davidklitzke - 26-Oct-2007 at 10:28am