Re: Wrong insert before trigger examples - Mailing list pgsql-docs

Patch applied back through PG 10.

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On Fri, Mar 13, 2020 at 06:56:37PM -0400, Bruce Momjian wrote:
> On Wed, Feb  5, 2020 at 09:36:49AM +0000, PG Doc comments form wrote:
> > The following documentation comment has been logged on the website:
> > 
> > Page: https://www.postgresql.org/docs/12/ddl-partitioning.html
> > Description:
> > 
> > Hi,
> > 
> > I just noticed that the example in 5.11.3.1. Point 5 contains an "before
> > insert trigger" which will not work anymore (I think since Postgres 12).
> > This trigger is not needed anymore and causes an error message.
> 
> Sorry for the delay in replying.  I was able to successfully create the
> trigger:
> 
>     CREATE TABLE measurement (
>         city_id         int not null,
>         logdate         date not null,
>         peaktemp        int,
>         unitsales       int
>     );
> 
>     CREATE TABLE measurement_y2006m02 (
>         CHECK ( logdate >= DATE '2006-02-01' AND logdate < DATE '2006-03-01' )
>     ) INHERITS (measurement);
> 
>     CREATE INDEX measurement_y2006m02_logdate ON measurement_y2006m02 (logdate);
> 
>     CREATE OR REPLACE FUNCTION measurement_insert_trigger()
>     RETURNS TRIGGER AS $$
>     BEGIN
>         INSERT INTO measurement_y2008m01 VALUES (NEW.*);
>         RETURN NULL;
>     END;
>     $$
>     LANGUAGE plpgsql;
> 
>     CREATE TRIGGER insert_measurement_trigger
>         BEFORE INSERT ON measurement
>         FOR EACH ROW EXECUTE FUNCTION measurement_insert_trigger();
> 
> There are actually two definitions of 'measurement' in the docs above,
> and you might have used the partitioned one:
> 
>     CREATE TABLE measurement (
>         city_id         int not null,
>         logdate         date not null,
>         peaktemp        int,
>         unitsales       int
>     ) PARTITION BY RANGE (logdate);
> 
> I have developed the attached patch to clarify which definition to use. 
> I am not sure if more extensive changes are needed.
> 
> -- 
>   Bruce Momjian  <bruce@momjian.us>        https://momjian.us
>   EnterpriseDB                             https://enterprisedb.com
> 
> + As you are, so once was I.  As I am, so you will be. +
> +                      Ancient Roman grave inscription +

> diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
> index 8d3a0d1c22..d2588876c0 100644
> --- a/doc/src/sgml/ddl.sgml
> +++ b/doc/src/sgml/ddl.sgml
> @@ -4103,8 +4103,8 @@ ALTER INDEX measurement_city_id_logdate_key
>       <title>Example</title>
>  
>       <para>
> -      We use the same <structname>measurement</structname> table we used
> -      above.  To implement partitioning using inheritance, use
> +      We use the non-partitioned <structname>measurement</structname>
> +      table above.  To implement partitioning using inheritance, use
>        the following steps:
>  
>        <orderedlist spacing="compact">


-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +