How to find sum of a column in a dataset based on another column variable.

Questions
1

Type value
A 12
B 8
C 10
A 2
B 3
C 10

out expected:
A 14
B 11
C 20
Similar to “Counts” function.
Note: I am a beginner, thanks in advance.

2

Is your data in a list of values:

{A,12,B,8,C,10,A,2,B,3,C,10}

or in 2D pairs:

{{A,12},{B,8},{C,10},{A,2},{B,3},{C,10}}

or an array:

{{A,a,12},{B,x,8},{C,q,10},{A,h,2},{B,d,3},{C,w,10}}

please clarify and provide example.

3

Hi LR,

List of pairs

list = {{"A", 12}, {"B", 8}, {"C", 10}, {"A", 2}, { "B", 3}, {"C", 10}}

GroupBy[list, First -> Last, Total] // Normal
(* {"A" -> 14, "B" -> 11, "C" -> 20} *)

List

list2 = {"A", 12, "B", 8, "C", 10, "A", 2, "B", 3, "C", 10}

list2 // Partition[#, 2] & // GroupBy[#, First -> Last, Total] & // Normal
4

Thank you everyone. Appreciate the replies.
It is a dataset (table) and I wanted an operation similar to Excel pivot table. This is what I did,
dataset[GroupBy[“Key”], Total, “Values”]
Any help to add multiple column values - Similar to pivot table. Thanks.

5

Please use the button (third from left) to provide some example rows of your table and also the operations you are trying to use.