From: Ferindo Middleton Jr <fmiddleton@verizon.net>
To: pgsql-sql@postgresql.org
Subject: showing multiple REFERENCE details of id fields in single query that share the same table
Date: Wed, 14 Sep 2005 21:11:37 -0400
Message-ID: <4328CA49.7030409@verizon.net> (raw)
I have a table which has two id fields which REFERENCE data back at
another table. It's setup like this:
class_prerequisite_bindings(id SERIAL, class_id INTEGER REFERENCES
classes(id), prerequisite INTEGER REFERENCES classes(id))
The classes table is like this:
classes(id SERIAL, course_title TEXT, course_code TEXT)
I have the following query:
SELECT * FROM class_prerequisite_bindings, classes WHERE
class_prerequisite_bindings.class_id = 64 AND
class_prerequisite_bindings.class_id = classes.id;
If I run the query above, the result will only give me info about the
class_id field matching id 64 back in the classes table. PROBLEM: I want
this query to also show the info about the prerequisite field which
would also have info at the classes table. This query will only show the
course_title and course_code of the class_id but I need this for the
prerequisite field as well. I think I need to do a JOIN, but I don't
understand how. How can I do this?
Ferindo
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To: pgsql-sql@postgresql.org
Cc: fmiddleton@verizon.net
Subject: Re: showing multiple REFERENCE details of id fields in single query that share the same table
In-Reply-To: <4328CA49.7030409@verizon.net>
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