Cannot convert lambda expression to type 'string' because it is not a delegate type

Question

The error is shown at select when i write next LINQ query:

DataTable dtbl = //...
int count = (from p in dtbl select p.RecordID).Max();

please help me out.

score 3 · Answer 1 · edited May 23 '17 at 10:33

3

Try this.

int count = dtbl.Max(p => p.RecordID);

Edit:

You can't easily use Linq on a DataTable.

edited May 23 '17 at 10:33

Community

answered Nov 02 '10 at 12:28

Daniel A. White

isn't that just rewriting it :D? – The_Butcher Nov 02 '10 at 12:30
@The_Butcher: It is and is better – abatishchev Nov 02 '10 at 12:30
@The_Butcher - no its not rewriting it. Its fixing the intention. – Daniel A. White Nov 02 '10 at 12:32
dtbl is a datatable. it is giving error "'System.Data.DataTable' does not contain a definition for 'Max' and no extension method 'Max' accepting a first argument of type 'System.Data.DataTable' could be found (are you missing a using directive or an assembly reference?)" when i add this line. – hari Nov 02 '10 at 12:33
Try dtbl.AsEnumerable().Max(p => p.RecordID); – Øyvind Bråthen Nov 02 '10 at 12:36
this link is helpful but i have done some rework thanks a lot – hari Nov 02 '10 at 13:01

score 0 · Answer 2 · answered Nov 02 '10 at 12:37

According to your comment that dtbl is a DataTable you can do:

int count = dtbl.AsEnumerable().Max(r => r.Field<int>("RecordID"));

You will need to add a reference to System.Data.DataSetExtensions.dll and add a using System.Data directive to the source file.

2 Answers2