In Linq or entity framework, we use IEnumerable and IQueryable for data manipulation or query data. IEnumerable is inherited by IQueryable , Hence IQueryable has all the features of IEnumerable and except this, it has its own features and benefits. Both have its own importance to query data and data manipulation in different situations in the application. we can go through with both the features and take the advantage of both the features to boost the LINQ Query performance. As per the need of application at some stage  IEnumerable is useful and some stage in the application  IQueryable is useful. Lets discuss about its use and features now. IEnumerable Features: IEnumerable exists in System.Collections Namespace. IEnumerable can move forward only over a collection, it can’t move backward and between the items. IEnumerable is best to query data from in-memory collections like List, Array etc. While query data from database, IEnumerable execute select query on server side,

Linq to sql is a microsofts powerful tool to develop critical application faster.In Linq to sql the query result is in Generic list of generic  ienumerable type.  If you want result set in DataTable you need to convert this generic list result into datatable. To convert LINQ to SQL results into a DataTable use following Code DataClassesDataContext dc=new DataClassesDataContext(); var results = dc.products.ToList(); DataTable dt = new DataTable(); List<product> lst = results; PropertyInfo[] props= typeof(product).GetProperties(); foreach (var prop in props) { dt.Columns.Add(prop.Name); } foreach (var item in lst) { var rowa = new object[props.Length]; for (int i = 0; i < props.Length; i++) { rowa[i] = props[i].GetValue(item, null); } dt.Rows.Add(rowa); } Gr