>in the case of a user with multiple shipping addresses...join user on address => you get the same user record for every instance of address, which then has to

>in the case of a user with multiple shipping addresses...join user on address => you get the same user record for every instance of address, which then has to be consolidated in code One solution is to use two queries: one to get the user with the user's key, then a second to get the addresses that match that user key. If you want to get all the user fields and all the addresses in one query, you can do a join with a group by on user and aggregate the addresses. In Postgres, you can aggregate into an array with array_agg(). More recent versions have json_agg() to aggregate into json. Under no circumstances should you have to deduplicate data in code. That's what the database is for. These queries can get tricky to write, but I view them as enjoyable puzzles, like writing regular expressions. The payoff for writing the right query is that it's faster than fetching too many records and deduplicating in client code, and the SQL is short and declarative.