Question

DataTable dtStock = new DataTable();
DataColumn dcTotalCases = new DataColumn("TotalCases");
dcTotalCases.DataType = System.Type.GetType("System.Int32");
dcTotalCases.ReadOnly = false;
dtStock.Columns.Add(dcTotalCases);

Method 1

int sum = Convert.ToInt32(dtStock.Compute("Sum([TotalCases]) ", "[TotalCases] <> ''"));

When I use this method, I get an error

Invalid usage of aggregate function Sum() and Type: String.

Method 2

int sum = Convert.ToInt32(dtStock.Compute("SUM(Convert([TotalCases], 'System.Int32'))", "");

When I use this method, I get an error

Syntax error in aggregate argument: Expecting a single column argument
with possible ‘Child’ qualifier.

Please help me…

Answer 1

I believe method #1 should work – just don’t compare your INT column to an empty string!!

So use something like this:

int sum = Convert.ToInt32(dtStock.Compute("Sum(TotalCases)", "[TotalCases] > 0"));

or

int sum = Convert.ToInt32(dtStock.Compute("Sum(TotalCases)", "[TotalCases] IS NOT NULL"));

or whatever you need – just don’t use [TotalCases] <> '' since that compares an INT to an empty string – and that’s not going to work!