Multivalue Field doubt

[SoumyaSengupta9]

I have 2 columns in a table each of which have 1 multivalue field.

ColumnA  ColumnB

abc              abc

def               ghi

ghi

jkl

I want to create a new column where i do an except between the 2 multivalue columns - i.e  as per the above table the result should be def, jkl.

I know we can use ->
| eval columnC = mvfilter(!match(column, searchText))
to achieve the same but the searchText needs to be static & i can't use another fields value. How can i achieve the result i want ?

[ITWhisperer]

| eval ColumnC=mvmap(ColumnA,if(isnull(mvfind(ColumnB,ColumnA)),ColumnA,null()))

Note, you need version 8.0.0 or better for the mvmap function.