https://www.infopathdev.com:443/blogs/ernesto/archive/2012/03/06/how-to-prevent-a-user-from-submitting-duplicate-data-to-dbxl.aspxImagine that your InfoPath form, which submits to DBXL, needs to make sure that there are no duplicate records. Using the web method QueryDocumentNodeSet, we can quickly check whether DBXL already contains a matching record. For the purposes of this tutorialenCommunityServer 2007 SP3 (Build: 31118.962)