Re: RULES and QUALIFICATION for INSERT - Mailing list pgsql-general

From Albe Laurenz
Subject Re: RULES and QUALIFICATION for INSERT
Date
Msg-id D960CB61B694CF459DCFB4B0128514C201E67743@exadv11.host.magwien.gv.at
Whole thread Raw
In response to RULES and QUALIFICATION for INSERT  (srdjan <srdjan.matic@anche.no>)
Responses Re: RULES and QUALIFICATION for INSERT  (srdjan <srdjan.matic@anche.no>)
List pgsql-general
srdjan wrote:
> I'll try to explain my problem with an example.
>
> -- I've got 2 tables and one view
> CREATE TABLE a (name varchar(20) primary key, num integer);
> CREATE TABLE b (town varchar(15), name varchar(20) references a(name));
>
> CREATE VIEW vvv AS SELECT * FROM a NATURAL JOIN b;
>
> -- I've crated a rule in this way
>
> CREATE RULE rrr AS ON INSERT TO vvv
> WHERE NEW.name = 'tom'
> DO INSTEAD
> INSERT INTO a VALUES (NEW.name, NEW.num);
>
> Trying a simple INSERT INTO vvv, I receive this message:
> ERROR: cannot insert into a view
> HINT: You need an unconditional ON INSERT DO INSTEAD rule.
>
> If I've understood well, the qualification (WHERE NEW.name = 'tom') is the condition under which the rule has to be
executed. 
> Only if the condition is met, the rule is executed.
> I noticed that if I remove the qualification, the rule works, but doing so
> I am not able anymore to test the condition. (I could overcame this problem
> with a trigger, but I'd prefer if someone could explain me how to do this with rules).

What is the desired response to

INSERT INTO vvv (name, town, num) VALUES ('Karl', 'Leipzig', 18);

Should this generate an error message, do nothing, or insert something?

Yours,
Laurenz Albe

pgsql-general by date:

Previous
From: "Albe Laurenz"
Date:
Subject: Re: Toast Table
Next
From: "josep porres"
Date:
Subject: pgplsql, how to save row variable to a table row