How to concatenate column data as comma-delimited values based on condition

[Anonymous]

I'm a newbie and need help for my table that contains customer purchases (TranId) from various channels (ChannelId).

Instead of having multiple records for the same customer transaction (TranId), I would like to have one record having a comma-delimited value listing of the channels (ChannelId) - either on the same or a new column - whichever is simpler to create. 

For example below, Customers A and C should have just one record having a comma-delimited value listing of various channels (ChannelId).

Current

Customer	TranId	ChannelId
A	1	10
A	1	11
B	2	10
C	3	11
C	3	12
D	4	13
D	5	10

Result

Customer	TranId	ChannelId
A	1	10,11
B	2	10
C	3	11,12
D	4	13
D	5	10

I appreciate any help!

[Nathaniel_C · Accepted solution]

Hi @Anonymous ,

Concatenatex =
CALCULATE (
    CONCATENATEX ( 'Table', 'Table'[ChannelId], ", " ),
    ALLEXCEPT ( 'Table', 'Table'[TranId] )
)

 
Let me know if you have any questions.

If this solves your issues, please mark it as the solution, so that others can find it easily. Kudos 👍are nice too.
Nathaniel