How did you know it was zip_code and not ZipCode?
Maybe in this case you know the same naming conventions are enforced across all tables. But in general it’s difficult to know the exact column name without looking it up first.
Maybe in this case you know the same naming conventions are enforced across all tables. But in general it’s difficult to know the exact column name without looking it up first.
I think you're missing the point; you start off with your goal, regardless of the column name. No one has the goal "we want columsn from this specific table", it's always "we want these columns in the final output".
No. The goal is to have an output column $FOO, where $FOO is meaningful and might not even be in the database in the first place.
> my goal is not to select created_at, my goal is to select Foo's created_at.
Then your goal is to get a value out of a specific table, namely `Foo`, presumably because the end-user wants to see some value in the results.
The end-user getting the value has neither an interest in nor knowledge of your schema. `Foo.created_at` is no more meaningful in the result sets than an unadorned `created_at`.
For this specific example, the end-user might want a column in the output called `age` (if it came from an inventory table`, or `duration` (if it came from a metrics tables), or perhaps `expiry` (if it is a table containing perishable stock). These are all a column in a Foo table, but the request that caused you to write the query in the first place does not mention table at all.
You get their requirement as either `age`, `duration`, `expiry` or similar. That is what you are starting from: "a need for a specific piece of data". You are not starting from "a need from a specific table", because the information needed is coming from someone who neither knows nor cares what your schema looks like.