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In-Reply-To: <81898782-7e51-30d1-b22b-09809085f534@pgmasters.net>
From: Thomas Munro <thomas.munro@gmail.com>
Date: Mon, 15 Mar 2021 15:47:15 +1300
Message-ID: 
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Subject: Re: Change JOIN tutorial to focus more on explicit joins
To: David Steele <david@pgmasters.net>
Cc: =?UTF-8?Q?J=C3=BCrgen_Purtz?= <juergen@purtz.de>,
	Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	"David G. Johnston" <david.g.johnston@gmail.com>
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On Thu, Mar 11, 2021 at 2:06 AM David Steele <david@pgmasters.net> wrote:
> On 12/1/20 3:38 AM, J=C3=BCrgen Purtz wrote:
> > OK. Patch attached.

+    Queries which access multiple tables (including repeats) at once are c=
alled

I'd write "Queries that" here (that's is a transatlantic difference in
usage; I try to proofread these things in American mode for
consistency with the rest of the language in this project, which I
probably don't entirely succeed at but this one I've learned...).

Maybe instead of "(including repeats)" it could say "(or multiple
instances of the same table)"?

+    For example, to return all the weather records together with the
location of the
+    associated city, the database compares the <structfield>city</structfi=
eld>
     column of each row of the <structname>weather</structname> table with =
the
     <structfield>name</structfield> column of all rows in the
<structname>cities</structname>
     table, and select the pairs of rows where these values match.

Here "select" should agree with "the database" and take an -s, no?

+    This syntax pre-dates the <literal>JOIN</literal> and <literal>ON</lit=
eral>
+    keywords.  The tables are simply listed in the <literal>FROM</literal>=
,
+    comma-separated, and the comparison expression added to the
+    <literal>WHERE</literal> clause.

Could we mention SQL92 somewhere?  Like maybe "This syntax pre-dates
the JOIN and ON keywords, which were introduced by SQL-92".  (That's a
"non-restrictive which", I think the clue is the comma?)