Hi Mike,

You need to program a few lines of code for that. CMSImport comes with an event system. Before a record gets imported it will raise the RecordImporting event. When you cancel that event the record will not be imported. Below a snippet how CMSImport will find a relation between your datasource and nodes in Umbraco and cancel the event when a document is found. So only new records will be imported.In the result screen you will see skipped records after import. These are the records that you've canceled using the event.

    public class CancelEvent :ApplicationBase
    {
        public CancelEvent()
        {
            // Wires up the event handler
            ContentImport.RecordImporting += new ContentImport.RecordImportingEventHandler(ContentImport_RecordImporting);
        }

        private void ContentImport_RecordImporting(object sender, RecordImportingEventArgs e)
        {
            //Cancel the importing event when a relation is found in the database
            e.Cancel = ContentRelation.GetRelatedDocument(e.DataAdapter, e.DataKeyName, e.DataKeyValue) != null;
        }
    }

To use this snippet add references to the dll's

- umbraco

- cms

- businesslogic

- interfaces

- Cmsimport.Extensions

This example will only work in PRO because of the relation that is only available in the PRO edition.

Hope this helps you, if not please let me know

Best,

Richard