Re: LEFT OUTER JOIN question - Mailing list pgsql-sql

Hi!

I expect the SELECT to return two rows. Would some kind
soul explain for me why it gives only one row?

TIA

CN
=============
CREATE TABLE x(c1 text,c2 int2);
INSERT INTO x VALUES('a',10);
INSERT INTO x VALUES('b',NULL);

CREATE TABLE y(c1 int2,c2 int2,c3 text);
INSERT INTO y VALUES(10,9,'yyy');

CREATE TABLE z(c1 text,c2 text);
INSERT INTO z VALUES('a','zzz');
INSERT INTO z VALUES('b','zzzz');

SELECT x.c1,y.c3,z.c2
FROM x JOIN z USING (c1)
 LEFT OUTER JOIN y ON (x.c2=y.c1)
WHERE y.c2=9;

 c1 | c3  | c2
----+-----+-----
 a  | yyy | zzz