re: left join
От | Silvio Macedo |
---|---|
Тема | re: left join |
Дата | |
Msg-id | Pine.LNX.4.04.9904261124480.4165-100000@emperor.inescn.pt обсуждение исходный текст |
Ответ на | left join (M Simms <grim@argh.demon.co.uk>) |
Ответы |
Trigger or Rule?
|
Список | pgsql-general |
>Is it just me, or is there no way to do a left join in postgresql? >Is there any way to do this, I have checked the documentation, looked >through the src, and there doesnt seem to be a reference to it >Any comments appreciated It's not you. :) :( IMHO, you could do somethink like: create table t1 ( field_A_of_t1 int, field_Bref_of_t1 int); create table t2 ( field_Aid_of_t2 int, field_B_of_t2 int); select field_A_of_t1, field_B_of_t2 from t1,t2 where field_A_of_t1 = SOMEVALUE and field_Aid_of_t2 = field_Bref_of_t1 union select field_A_of_t1, null from t1 where field_A_of_t1 = SOMEVALUE and field_Bref_of_t1 is null order by field_B_of_t2; (I've just checked this - it works.) Note - using somethink like ... and (field_Aid_of_t2=field_Bref_of_t1 or field_Bref_of_t1 is null) will not work (you'ld have the product). I would appreciate if someone verified this suggestion . ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ````````````````````````````````````````````` Silvio Emanuel Nunes Barbosa de Macedo mailto:smacedo@inescn.pt INESC - Porto - Grupo CAV Pc da Republica, 93 R/C Tel:351 2 209 42 21 4000 PORTO PORTUGAL Fax:351 2 208 41 72
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