Check if site exists in another dataset, then remove from list if exists - ETL

louiswatson

Hi, I have a list of sites which have been joined from two datasets in an ETL using a field called 'Database Number'. This is working as expected.

I want to then check whether this 'Database Number' exists in dataset 3, if it does, it means that we are working on this deal and therefore don't need this included in the list. Is there a way for me to check if a site already exists in a dataset and then remove from the list?

I tried using a full outer join but that just showed a list of sites that do exist in the dataset, which is the opposite of what I'm trying to achieve.

Hopefully this makes sense but let me know if any additional information is needed!

Thankyou in advance.

GrantSmith

Hi @louiswatson

You can do a left join from your existing dataset to your dataset 3 based on the Database Number. If the right table's Database Number is NULL then it doesn't exist in the left table. You can do a left join (or right join) and then filter on a NULL value.

GrantSmith

Hi @louiswatson

You can do a left join from your existing dataset to your dataset 3 based on the Database Number. If the right table's Database Number is NULL then it doesn't exist in the left table. You can do a left join (or right join) and then filter on a NULL value.