> That was strange.. This is not how it worked for me in sqlite3. It was more this way:
The author needs to visit the grammar for SELECT and specifically expand the `join-operator` grammar; he will see that the diagram that he drew the red arrow on is, in fact, going through the grammar diagram as it is listed. (The join operator here is the "," used to separate the tables.)
Also, I feel like we keep using "with-clause" to mean "where clause".
Now, what the semantic meaning of this grammar is, and whether that was a bug … not sure. Syntactically, it seems ok, but I agree with the "semi explicit join" pondering of the author. PostgreSQL's docs, for example, indicate that this is not syntactically valid.
The blog indicates they believe
SELECT * FROM table1, table2 ON table1.id=table2.id;
join-clause=table1, table2 ON table1.id=table2.id