From: thomas at tada.se (Thomas Hallgren)
Date: Tue, 15 Aug 2006 00:44:49 +0200
Subject: [Pljava-dev] Custom java objects
In-Reply-To: <12743.060808@yandex.ru>
References: <12743.060808@yandex.ru>
Message-ID: <44E0FCE1.6020609@tada.se>

Hi Maxim,
You should be able to do this by just installing a custom type mapping for type 'a'. See: 
http://wiki.tada.se/wiki/display/pljava/Mapping+an+SQL+type+to+a+Java+class

Regards,
Thomas Hallgren

Maxim wrote:
> Hello,
> 
> I try to write aggregate function in Java for PostgeeSQL 8.1.
> 
> I just want to know, are there any ways to pass custom java objects
> thorough iterations of row handler?
> 
> For example, I have functions in PostgreSQL (a is a table):
> 
> CREATE FUNCTION handler1(a, a)
> returns a
> as 'functions.handler1'
> immutable language java;
> 
> CREATE FUNCTION handler2(a)
> returns a
> as 'functions.handler2'
> immutable language java;
> 
> CREATE AGGREGATE aa ( BASETYPE = a, SFUNC = handler1, STYPE = a, FINALFUNC = handler2);
> 
> 
> And two functions in Java:
> 
>     public static boolean handler1(ResultSet a, ResultSet record, ResultSet result) throws Exception {
>         int v = a == null ? Integer.MIN_VALUE : a.getInt(1);
>         if (record.getInt(1) > v) {
>             result.updateInt(1, record.getInt(1));
>             result.updateString(2, record.getString(2));
>         } else {
>             result.updateInt(1, a.getInt(1));
>             result.updateString(2, a.getString(2));
>         }
>         return true;
>     }
> 
>     public static boolean handler2(ResultSet a, ResultSet result) throws Exception {
>         if (a == null) return false;
>         result.updateInt(1, a.getInt(1));
>         result.updateString(2, a.getString(2));
>         return true;
>     }
> 
>     
> I Just want to use custom java object instead of "ResultSet a".
> 
> 
>