Unsupported Functionality (LINQ to SQL)
In LINQ to SQL, the following SQL functionality cannot be exposed through translation of existing common language runtime (CLR) and .NET Framework constructs:
STDDEV
LIKE
Although LIKE is not supported through direct translation, similar functionality exists in the SqlMethods class. For more information, see [M:System.Data.Linq.SqlClient.SqlMethods.Like(System.String,System.String].
DATEDIFF
LINQ to SQL has limited support for DATEDIFF. Similar functionality exists in the SqlMethods class.
ROUND
LINQ to SQL has limited support for ROUND. For more information, see System.Math Methods (LINQ to SQL).