How to only show the destination not in the search table?

[Miguel3393]

Hello,

I have a lookup table with numbers, where it checks the numbers that match the error_code 11.

index="cdrs" "error_code"="11" "Destino"="*"

| lookup DIDREPEP Destino OUTPUT Destino | table Destino

But it shows some blank results because they are not in the lookup table.
How can I do so that it only shows me the destination that is not in the search table?.

thanks greetings.

[paulcurry · Accepted solution]

Maybe try: 

index="cdrs" "error_code"="11" "Destino"="*"

| lookup DIDREPEP Destino OUTPUT Destino AS foundInLookup

|where isnull(FoundInLookup)