Thread: trigger or something else?

Hello,

I have a table that has to have several fields with different names, 
but equal content. Sounds stupid, but it is because I have 2 
different programs querying the same table for user information and 
each of them uses differently named fields.

Eg. I have fields passwd and password.
When passwd field changes, password must automatically change 
to be the same as passwd.

I was wondering whether I need a trigger for that, or could I 
somehow manage to specify that in the "create table" stmt.

If I need to do it via trigger, then I apparently need the plpgsql, right?
Could you tell which configure option enables that? --enable-
plpgsql? 

Thanks in advamce for any comments.

Emils

On Wed, 28 Jun 2000, Emils Klotins wrote:

> Hello,
> 
> I have a table that has to have several fields with different names, 
> but equal content. Sounds stupid, but it is because I have 2 
> different programs querying the same table for user information and 
> each of them uses differently named fields.
Why you not use any VIEW, for example:

CREATE TABLE xxx (a text);
CREATE VIEW v_xxx AS select a as field1, a as field2 from xxx;

test=> INSERT INTO xxx VALUES ('qqqqq');
INSERT 380446 1
test=> SELECT * FROM v_xxx;field1 | field2
--------+--------qqqqq  | qqqqq
(1 row)
                Karel

>>>>> "EK" == Emils Klotins <emils@dot.lv> writes:
EK> Hello,EK> I have a table that has to have several fields with different names, EK> but equal content. Sounds
stupid,but it is because I have 2 EK> different programs querying the same table for user information and EK> each of
themuses differently named fields.
 
EK> Eg. I have fields passwd and password.EK> When passwd field changes, password must automatically change EK> to be
thesame as passwd.
 
EK> I was wondering whether I need a trigger for that, or could I EK> somehow manage to specify that in the "create
table"stmt.
 
EK> If I need to do it via trigger, then I apparently need the plpgsql, right?EK> Could you tell which configure option
enablesthat? --enable-EK> plpgsql? 
 
EK> Thanks in advamce for any comments.
EK> Emils

I suppose you can use view for your need. For example:

create table a ( l varchar(30), p varchar(30)
);

create view b as select l as login, p as password from a;

insert into a values ('qq', 'ww');
select * from b;
tolik=# select * from b;login | password 
-------+----------qq    | ww
(1 rows)


Unfortunately this way suits for select only, not for 'insert into b'
and 'update b' statement.

-- 
Anatoly K. Lasareff              Email:       tolik@aaanet.ru 

> I suppose you can use view for your need. For example:
>

...

> Unfortunately this way suits for select only, not for 'insert into b'
> and 'update b' statement.
>

Except that you can use rules to update/insert data into tables when an
insert/update is done on the view. See  the docs for details on how to do this.

>
> --
> Anatoly K. Lasareff              Email:       tolik@aaanet.ru

Grant

--
> Poorly planned software requires a genius to write it
> and a hero to use it.

Grant Finnemore BSc(Eng)  (mailto:gaf@ucs.co.za)
Software Engineer         Universal Computer Services
Tel  (+27)(11)712-1366    PO Box 31266 Braamfontein 2017, South Africa
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