.net-3.5 - Read For Learn

LINQ query on a 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,

LINQ’s Distinct() on a particular property

EDIT: This is now part of MoreLINQ. What you need is a “distinct-by” effectively. I don’t believe it’s part of LINQ as it stands, although it’s fairly easy to write: So to find the distinct values using just the Id property, you could use: And to use multiple properties, you can use anonymous types, which implement equality appropriately: … Read more