How to sum the column in a data table?

Dinesh Santhalingam

I have a data table .I want to sum the column and append it to an array.

Name	Count	Time
A	5	1/1/2017 10:00:00AM
B	4	1/1/2017 10:00:00AM
C	5	1/1/2017 10:00:00AM
D	2	1/1/2017 10:00:00AM
E	3	1/1/2017 11:00:00AM
F	3	1/1/2017 11:00:00AM
G	4	1/1/2017 11:00:00AM
H	5	1/1/2017 11:00:00AM
I	2	1/1/2017 12:00:00AM
J	3	1/1/2017 12:00:00AM
K	5	1/1/2017 12:00:00AM
L	6	1/1/2017 12:00:00AM

I Want to add the count column if the Time in column is same. (Ex:)The time (1/1/2017 10:00:00AM) Same for A,B,C,D. So i want to add the count column of A,B,C,D .How to do this .please help me to solve this issue.

7 Replies

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Rafnas T P9y ago
if you want count based on Time then you need to remove Name column and you have to do group by Time try below line

dt.Columns.RemoveAt(0);
dt.AcceptChanges();
dt= dt.AsEnumerable().GroupBy(r => r.Field("Time")).Select(g => g.First()).CopyToDataTable();
Nitin Sontakke9y ago
Just out of curiosity, where is the original data? I assume it must be in some sort of database system.

Why you are not doing it there itself? It would be lot quicker and also easier. Typically, it is the job of database engine and it is better that every layer does it's own job.
Amit Gupta9y ago
You can use linq for that and groupby date.

Follow the link
http://stackoverflow.com/questions/7736831/group-by-in-datatable-column-sum

http://stackoverflow.com/questions/11574474/linq-get-sum-of-data-group-by-date
Dinesh Santhalingam9y ago
Actually there were more number of rows.The date is common for every four rows.
Ex: Time will be 1/1/2017 10:00:00AM for first four rows.Then time is changed for next four rows.this will repeating .Now iwant to sum the count if time is same .
Amit Gupta9y ago
It would be helpful, if you elaborate your requirement properly.

Means you want to pass only date?
Then you can use like operator "time like _time%"; where _time contains only date part.

Do let me know, if it solves your problem
Dinesh Santhalingam9y ago
There were more number of columns .So How to i give the time by manually .Its not posssible.But the Method of sum is correct.
Amit Gupta9y ago
Try this
String _time ="1/1/2017 10:00:00 AM";
var total = (int)datatable.Compute ("Sum (count)", "time =_time");