I believe a comma is basically an inner join with no ON clause. I think this covers it https://www.sqlite.org/lang_select.html#fromclause "If the join-operator is "CROSS JOIN", "INNER JOIN", "JOIN" or a comma (",") and there is no ON or USING clause, then the result of the join is simply the cartesian product of the left and right-hand datasets."
So it's basically a personal preference. Similar to how it's been noted that for inner joins, putting the constraint in the ON clause or there WHERE clause results in the same meaning. (For my personal preference the comma thing is one of those things that drives me completely batty every time I see it. But that's just the way my brain works when reading or creating a query) -----Original Message----- From: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] On Behalf Of Dominique Devienne Sent: Wednesday, February 27, 2019 9:06 AM To: SQLite mailing list Subject: Re: [sqlite] Getting data from two JOIN tables On Wed, Feb 27, 2019 at 2:18 PM Jose Isaias Cabrera <jic...@outlook.com> wrote: > Thanks. This is exactly what I needed. So, there is really no JOIN here, > or is the "from t outer_t, z outer_z" a JOIN like statement? Where can I > read more about this? And yes, your assessment of t(a, idate) and z(f, > idate) being unique are true. > Yes there is: select ... > from t outer_t, z outer_z > where a == f > and a == 'p001' > and ... > That's equivalent to select ... from t outer_t join z outer_z on t.a = z.f With additional where clauses involving correlated subqueries to determine the max(idate) on both sides, given a given a value (and thus f value too, given the join condition). At least that's how I read it. --DD _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
