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Niraj Chourasia

Hi there,

I have 2 tables A and B. I need to gets all records of table A which does not exists in table B.

I could'nt get the way to do this. Please guide me to achieve it.

Thanks

Facundo Lucci

Hi Niraj,
Community member here. I’m not sure of the best way with limited details and context. But, assuming there is a field with unique values in table A that matches a field in table B. I would start with adding a query all records function to your stack.
(“+” > Database Requests > Query all Records > table A)
Then, in the Filter tab add table B “by joins” no conditionals needed. Hit save.
Then add a conditional “by custom query” where tableA.matching_field does not equal tableB.matching_field. Hit save.
That should return an array of what I think you are looking for.
Lastly, I would also check out this great video that shows the true potential of add-ons and joins. https://youtu.be/3T8DQ6aAQBw

Niraj Chourasia

Hi  ,
table A unique id field is used as foreign key in table B as user id

Niraj Chourasia

Hi  ,

I tried according to your suggestion but could'nt succeed, query always returing all records of table A

[Xano (6).png]

Niraj Chourasia

anybody can look into this ?

Facundo Lucci

Hey my bad I thought because it works with equals it would work with not equals. But, that’s not how joins work.

So what you want to do is add table B as a “left” join. Then add the conditional to that join where table A.id = table B.user_id. Then add custom query where table B.user_id = null. (Just tested and it worked.)
[F03649FC-ACDB-4B81-96BC-CAA5166428DD]
As far I understand this will create a table “a” with all records of tableA (which is why we kept getting all the records) joined with the matching records in B based on the conditional set. If there is no match it will add null match.

Gi Ma

 Thank you for this contribution!