Column comparison

[AmateurBI]

Hi everybody,

i'm completely unfamiliar with PowerBI and just started using ist two days ago. I am getting a list of product names every month. That list is constantly growing and already to big to open it in Excel. I tried to open it with Notepad ++ and split it into different sheets but that doesn't work, either...

What I want to do is, upload the lists that come in every month and compare it to one from the month before and see which names are still in the list and which ones disappeared. Is that possible? I tried to do it with a Related function and joins, but it won't work out...

Can anyone help me out?

[Greg_Deckler]

You should be able to do this in M code, just a simple join (Merge) query.

[AmateurBI]

How and where can I do that exactly? I was able to join the two tables, but the result was incorrect

[v-caliao-msft]

@AmateurBI,

You could use Merge queries feature. 
Sample data:

Product name for Jan  

Product Name
A
B
C
D
E
F
G
H
I
J
K
L

Product name for Feb

Product Name
B
D
E
F
G
Y
I
J
K
M

Edit query>Merge queries

Results

For the null row which indicates the product names disappear, for the rows that have values, it indicates the product names are still in the list.

Reference

https://powerbi.microsoft.com/en-us/documentation/powerbi-desktop-shape-and-combine-data/

Regards,

Charlie Liao

[AmateurBI]

Hey Charlie,

thank you so much for your reply! I tried to put whatever comes out of the in a new table with merge as new query (My PowerBi is in German, not sure whether translation is correct) because when I just tried to merge the queries this appeared:

This is the code that is displayed: = Table.NestedJoin(#"March",{"Names"},#"April",{"Names"},"NewColumn",JoinKind.LeftOuter)

So I don't really understand why PowerBi is just adding a new column? And there is only the expression "Table" in it?

When i put it in a new empty query it worked better, but now of course I can't really see the names that disappeared, but only the names that matched in both columns...

= Table.NestedJoin(#"March",{"Names"},#"April",{"Names"},"NewColumn.1",JoinKind.LeftOuter)

[v-caliao-msft · Accepted solution]

@AmateurBI,

You need to expand this table.

Regards,

Charlie Liao

[AmateurBI]

That was exactly, what I was looking for! Thank you so much