lookup value and replace value on ecolumn power Query

[dats]

Hello,

I am trying to reclass/replace values in Table A column GTIN based on what is stated in Table B column GTIN.NEW

I am loading some data (500.00 rows and 10 columns to power bi) in Table A and Table B has 2 columns and a few rows.

In example this is what table a looks like:

Productname	GTIN	Value	Volume
Bikes	123	100	1
Cars	456	300	1

This is my data table A.

Now I have a second table B which has to columns:

GTIN	GTIN.NEW
123	111
456	222

I know i could do this after loading all the data and create a calculated column and use the lookupvalue function but is there a way to do this before loading the data into the model using power query? Would you recommend it in terms of performance?

Kr 🙂

[dats]

I might add that table B does not have the same amount of entries ass Table A. Table B only consists of the GTINs that need to be changed 

[PaulDBrown]

@dats 

From the sound of it you could merge both tables in Power Query by linking the GTIN columns. 
Then delete the old GTIN column once the merge table is created

[dats]

@PaulDBrown that would only work if table B has the same GTIN entries as table A, or?

[PaulDBrown · Accepted solution]

@dats 

It will still work. You will get null for rows where the GTINs values do not coincide. You can the create a new conditional column to select either the new or the old value, and finally delete the previous GTIN columns

[dats]

@PaulDBrownthanks. This worked as needed