Check if value in column B exists in column A

[webportal]

Using Power Query, I need to check for each row of MyTable if the value in column B exists in column A.

If it does, then that value should be returned, then an empy field.

This is the code I'm trying to enter into an if statement somehow:

Table.Contains(MyTable,[B],[A])

Which is returing a cyclical reference error.

[artemus]

Assuming this is in AddColumns...

Just use:

if Text.Contains([A], [B]) then
    [B]
else
   null

[webportal]

Hi @artemus 

thanks, it always returns B (since B is a substring of A).

I need to make an exact comparison, is there a function for that?

[artemus]

Oh, just use:

if [A] = [B] then
    [A]
else
    null

[webportal]

Hi, that makes a comparison row by row which always returns false (null).
I need to check if column B exists in the entire column A.

[artemus]

I think I see what you are getting at.

In this case instead of adding a column, do a self join. Just do a merge on the same table using [A] and [B] as the join columns