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Datatable grouping

Posted on 2014-12-30
Medium Priority
Last Modified: 2014-12-30

I have data table and example of the data could be this

Key    Data
1        5
2        2
1        1
3        4

I need some way of grouping and summing the data so that what I end with is this:

Key    Data
1        6
2        2
3        4

Basically I need the key column to unique and the data column to be the sum of all the common key values

Is this even possible?
Question by:andyw27
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Expert Comment

by:Ali HND
ID: 40523929
SELECT key,  SUM (data)  FROM YourTableName  GROUP BY key;

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Author Comment

ID: 40523941
Sorry, its a data table, not a SQL table

Accepted Solution

Ali HND earned 2000 total points
ID: 40523970
If your columns was:
Imports System.Data
Imports System.Linq

Class Program
	Private Shared Sub Main(args As String())
		Dim table As New DataTable()

		Dim query = From grp In From row In table.AsEnumerable()Group row By row.Field(Of Integer)("Id")Order By grp.KeyNew With { _
			Key .Id = grp.Key, _
			Key .Sum = grp.Sum(Function(r) r.Field(Of Decimal)("Value")) _

		For Each grp As var In query
			Console.WriteLine("{0}" & vbTab & "{1}", grp.Id, grp.Sum)
	End Sub
End Class

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LVL 71

Expert Comment

ID: 40523973
I reckon you need to go thru the table and sum up the values yourself.

Author Closing Comment

ID: 40524369
Many Thanks, a particularly useful answer.

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