Re: SELECT help (fwd)
От | Steve Boyle \(Roselink\) |
---|---|
Тема | Re: SELECT help (fwd) |
Дата | |
Msg-id | 00c601c19dba$adc7e0c0$c55869d5@dualtower обсуждение исходный текст |
Ответ на | SELECT help (fwd) (David A Dickson <davidd@saraswati.wcg.mcgill.ca>) |
Список | pgsql-general |
David, I think you will need to use an outer join to get the title=0 records look at: http://www.postgresql.org/idocs/index.php?queries.html#QUERIES-FROM specifically the information relating to Left Outer Join. hih steve boyle ----- Original Message ----- From: "David A Dickson" <davidd@saraswati.wcg.mcgill.ca> To: <pgsql-general@postgresql.org> Sent: Monday, January 14, 2002 6:17 PM Subject: [GENERAL] SELECT help (fwd) > I am trying to do a select similar to the one below: > > SELECT individual.first, individual.last, title_value.title > FROM individual, title_value, individual_staff_join_unit > WHERE individual.individual_id = 5307809 > AND > individual_staff_join_unit.main_id = individual.main_id > AND > title_value.title_id = individual_staff_join_unit.title_id; > > Table "individual" > Attribute | Type | Modifier > ------------------+------------------------+---------- > individual_id | integer | > main_id | integer | > first | character varying(40) | > last | character varying(40) | > > Table "individual_staff_join_unit" > Attribute | Type | Modifier > -------------+---------+---------- > main_id | integer | > unit_id | integer | > title_id | integer | > > Table "title_value" > Attribute | Type | Modifier > -----------+-----------------------+---------- > title_id | integer | > title | character varying(40) | > > Every individual has a individual_id and a main_id. > > The problem is that some rows in the individual_staff_join_unit table have > title_id = 0 and there is no row in title_value with title = 0. If this is > the case then no row is retrieved for the above SELECT. > > Q: Is it possible to still get the individual.first and individual.last > from the table if the individual_staff_join_unit.title_id = 0 using only > one select statement and without modifying any of the tables, and to get > individual.first, individual.last and title_value.title if > individual_staff_join_unit.title_id != 0? > > -- > David A Dickson > david.dickson@mail.mcgill.ca > > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/users-lounge/docs/faq.html >
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