Re: Insert into VIEW using RULE. Not possible to use nextval()? - Mailing list pgsql-sql

Hi Richard,

Your situation is the same as mine.  The only difference is that I
actually had a call to nextval() in the actual call to the VIEW.  In
your case this would be something like "INSERT INTO
Vschematic_insert(...".  So if you were to try "INSERT INTO
Vschematic_insert(nextval('foo_sql'), ..." and then try to use that
value inside the RULE it will fail.

Your solution works great assuming two things:
1. You don't need to use the ID for anything else (which is true in
your case and actually in mine as well)
2. currval() is guaranteed to be correct within the RULE.  This was my
second question.  If I call "INSERT INTO Vschematic_insert(..."
simultaneously 1000 times is it guaranteed to be correct?

On 5/3/07, Richard Broersma Jr <rabroersma@yahoo.com> wrote:
>
> --- Collin Peters <cadiolis@gmail.com> wrote:
>
> > The exact problem is that you can't use nextval() with an INSERTable VIEW
>
> I apoligize if I am not understanding your problem correctly.  I am unsure as to intent behind
> using nextval() as opposed to currval().
>
> I do not know if the following DDL will help but I can show you how I preform inserts across
> multiple tables using the rule system:
>
> CREATE RULE Vschematic_insert AS ON INSERT TO Docs.Vschematic
> DO INSTEAD (
>         INSERT INTO Docs.Document ( did, doccode, docnum, docdisc)
>         VALUES ( DEFAULT, 'schematic', New.docnum, New.docdisc);
>
>         INSERT INTO Docs.Drawing ( did, doccode, title1, title2, title3)
>         VALUES ( Currval('Docs.Document_did_seq'), 'schematic', New.title1, New.title2, New.title3);
>
>         INSERT INTO Docs.Schematic ( did, doccode)
>         VALUES ( Currval('Docs.Document_did_seq'), 'schematic')
>            );
>
> For reference the table DDL follows:
>
> CREATE TABLE docs.document (
>         did             serial          PRIMARY KEY,
>         doccode         varchar(30)     not null,
>         docnum          varchar(30)     unique not null,
>         docdisc         text            not null default '',
>
>         constraint
>         document_doccode_chk
>         check ( doccode in ( 'cpf', 'logicsystem', 'processdetail',
>                         'electricaldetail', 'locationplan', 'logicdiagram',
>                         'loopdiagram', 'schematic', 'wiringdiagram', 'pid',
>                         'isometric', 'airsupplydetail', 'mountingdetail',
>                         'pnuematicdetail', 'functionaldiscription',
>                         'datasheet', 'processmaterialspec',
>                         'loopfoldermiscellaneous', 'loopfolderorficeplate',
>                         'loopfolderinstallation', 'loopfolderswitch',
>                         'loopfolderxmtrctrlind', 'loopfoldercontrolvalve',
>                         'loopfolderanalyzer', 'loopfolderworkscope',
>                         'loopfolderdocumentation')));
>
> CREATE TABLE docs.drawing
> (
>         did             integer         primary key references
>                                         docs.document(did) on delete cascade,
>         doccode         varchar(30)     not null,
>         title1          varchar(50)     not null,
>         title2          varchar(50)     not null,
>         title3          varchar(50)     not null,
>
>         constraint
>         drawing_doccode_chk
>         check   ( doccode in ( 'processdetail', 'electricaldetail', 'locationplan',
>                                 'logicdiagram', 'loopdiagram', 'schematic', 'pid',
>                                 'isometric', 'airsupplydetail', 'mountingdetail',
>                                 'pnuematicdetail'))) ;
>
> CREATE TABLE docs.schematic
> (
>         did             integer         primary key references
>                                         docs.drawing(did) on delete cascade,
>         doccode         varchar(30)     not null,
>         cid             integer         references equ.lcp(cid),
>
>         constraint
>         schematic_doccode_chk
>         check ( doccode = 'schematic')) ;
>
> Regards,
> Richard Broersma Jr.
>