Filtering two datatables using ado.net

I have two datatables which are populating from two different tables of two different databases. I want to get all the records of first datatable which are not in 2nd datatable. I ‘m using the following piece of code.

odr = oDs.Tables(0).Select("Sno = (SELECT SNO FROM " + Convert.ToString(oDataSetChanges.Tables(0)) + ")")

or this one

odr = oDs.Tables(0).Select("Sno NOT IN (SELECT " + Convert.ToString(oDataSetChanges.Tables(0).Columns ("SNO")) + " FROM " + Convert.ToString(oDataSetChanges.Tables(0)) + ")")

or I tried the following code as well

oDv1.RowFilter = "Sno NOT IN (SELECT SNO FROM " + Convert.ToString(oDv2.Table) + ")"

where SNO are the primary key columns of both tables but by using all these code I got the same syntax error that is


Message "Syntax error: Missing operand after 'SNO' operator."



Kindly help me in this reagard ASAP



Thanx in advance