Joining datatables problem Left Join where b.key is NULL

Hi I want to join 2 datatables so that I can create a list of items that are in table A but that are not in table B

In SQL it would be something like this

Select A.*
FROM tableA A
LEFT JOIN TableB B
ON A.key=B.key
WHERE B.key is NULL

as far as I can tell it can’t be done with the Join activity.

Does anyone have any ideas please?

Many thanks,

Hi @charliefik

Did you try the Join Tables activity? It is has an interface to set the options you want, please let me know if that works for you

Hi Andres,

I did already try the Join Tables activity I couldn’t see how to set the Where B.key is NULL part. I tried adding another row and putting NULL=B.key essentially but that didn’t work

Actually, I don’t think you can do that type of join in the Join Table Activity. I think you want a Left Exclusive join.

See this documentation:

In this case, from the top of my head, you might consider:

  • Programmatically do a join
  • Use Linq to join
  • If the tables come from a database, you might want to do a sql query join, using the db activities.
  • If the tables come from excel, maybe look into the possibility of using VBA or power query.

Thanks Benny,

That’s what I thought.