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Two unrelated tables, one query...

Two unrelated tables, one query...

Two unrelated tables, one query...

I have two unrelated tables which I want to get info from for one query, each needs to be joined against another table...

I'm doing this in postgres, but I'm imagining it's a standard SQL question so I'm posting here... essentially, I want


SELECT email.email, url.url
      FROM email, url
      JOIN account_has_email ON contactemail.email_id = email.email_id
      JOIN account_has_url ON account_has_url.url_id = url.url_id
      WHERE contactemail.customer_id=5 AND account_has_url.customer_id=5

And no, there's no table where customer_id is listed to start from and join against as it's a FK to an entirely separate database. I have a feeling this is easy and I'm brainfarting, but I'd really appreciate a leg up on this one. Thanks.

RE: Two unrelated tables, one query...

Posted, then I figured it out... doh... for anyone who may care


SELECT email.email, url.url
      FROM account_has_email
      JOIN account_has_url ON account_has_email.customer_id = account_has_url.customer_id
      JOIN email ON account_has_email.email_id = email.email_id
      JOIN url ON url.url_id = account_has_url.url_id
      WHERE account_has_email.customer_id = 5
Obviously some shortcoming to this method if email/url doesn't exist etc... but here's what I was looking for.

RE: Two unrelated tables, one query...

if there is information in one table and not in the other and you want to include that information, you have to do outer joins.  See the link below for more info.


Anything worth doing is a lot more difficult than it's worth - Unknown Induhvidual

Essential reading for anyone working with databases:
The Fundamentals of Relational Database Design
Understanding SQL Joins

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