From: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
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To: | PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
Subject: | Select Reference Page - Make Join Syntax More Prominent |
Date: | 2022-05-06 16:19:23 |
Message-ID: | CAKFQuwbiUM5cb1WJXQZP8xNCW6J0zJ2YAmMaFnwes8hAUhrmwA@mail.gmail.com |
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Lists: | pgsql-hackers |
Hey,
Looking again at the SELECT Reference page while helping a novice user I
was once again annoyed but how the most common query syntax form for the
FROM clause is buried within a bunch of "how to generate a table" detail.
In this specific case I also was trying to describe why when you have three
tables to join that you can build a join tree and only actually use a
single from_item (IOW, no commas are required/allowed). From there it
became clear that from_item is serving two roles here and introducing a
structural element (join_expression) to represent the commonly used join
tree query form made sense. I then modelled the tree-like nature (using
the term recursive for now) explicitly as the left side of the join can be
either a new join_expression, extending the tree, or a from_item, bringing
the tree to its end.
In the description I had to move LATERAL up above all the join stuff since
it pertains to from_item and I wanted to call out the final set of
parameters as all being related to the join tree.
I'll do a pass at making sure we are using consistent terminology if this
has a shot of getting committed.
I've attached the patch and the resulting html page.
David J.
Attachment | Content-Type | Size |
---|---|---|
SELECT.html | text/html | 107.9 KB |
v0001-select-reference-more-prominent-join-syntax.diff | application/octet-stream | 10.8 KB |
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