datatable

You can’t query against the DataTable‘s Rows collection, since DataRowCollection doesn’t implement IEnumerable<T>. You need to use the AsEnumerable() extension for DataTable. Like so: And as @Keith says, you’ll need to add a reference to System.Data.DataSetExtensions AsEnumerable() returns IEnumerable<DataRow>. If you need to convert IEnumerable<DataRow> to a DataTable, use the CopyToDataTable() extension. Below is query with Lambda Expression,