On Thu, Mar 11, 2021 at 2:06 AM David Steele <da...@pgmasters.net> wrote:
> On 12/1/20 3:38 AM, Jürgen Purtz wrote:
> > OK. Patch attached.
+ Queries which access multiple tables (including repeats) at once are called
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</structfield>
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</literal>
+ 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?)
