Re: Simple SQL question

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От Daniel Henrique Alves Lima
Тема Re: Simple SQL question
Дата
Msg-id 404D4667.10206@yahoo.com.br
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Ответ на Simple SQL question  (Daniel Henrique Alves Lima <email_daniel_h@yahoo.com.br>)
Список pgsql-sql
Thank you, Jeremy.

I've built a function that returns a string from (cd_teacher, cd_course) 
and i've create a functional index over this function, like :

create index teacher_course_idx on teacher_course 
(build_unique_2p(cd_teacher,cd_course));
select * from teacher_course where build_unique_2p(cd_teacher,cd_course) 
in ('1:2','23:11','563','341');

Is it possible to use "array cast" over cd_teacher and cd_course (just 
an idea, i don't known the sintaxe), like:

select * from teachar_course where cast((cd_teacher,cd_course) as array) 
in ('{1,2}','{23,11}','{563,341}');

?

I'm using postgreSQL 7.34

Thanks !!!

Jeremy Semeiks wrote:

>You could use a subselect of unions:
>
>select * from teacher_course where (cd_course, cd_teacher) in
>(select 1, 2 union select 23, 11 union select 563, 341)
>
>Maybe there's a more concise way, though.
>
>- Jeremy
>
>  
>




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