Nelson A. de Oliveira wrote:
Hi!
On Tue, Jul 17, 2012 at 7:36 PM, Daniel Serodio (lists)
<daniel.li...@mandic.com.br> wrote:
I'm using pgAdmin 1.14.3, and its Graphical Query Builder generates WHERE
clauses for joins. It would be nice if it generated JOIN clauses instead.
Is there any kind of difference between WHERE or JOINs in PostgreSQL?
Aren't they all a cartesian product internally?
They may be implemented the same way in PostgresSQL, but they're two
different concepts. Because of this, I find it a lot easier to
understand a complex query when the joins are in a JOIN clause.
In more practical terms, it's easier to change "a JOIN b ON a.pk = b.fk"
to "a LEFT JOIN b ON a.pk = b.fk" (just have to type the LEFT keyword,
regardless of which tables/columns are used) then change "WHERE a.pk =
b.fk" to "WHERE a.pk = b.fk OR b.fk IS NULL" (have to add "OR b.fk IS
NULL", which changes according to which tables/columns are used).
Regards,
Daniel Serodio
