[Pljava-dev] Custom java objects

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".

--
Best regards,
Maxim Karavaev,
ISP RAS (www.ispras.ru)

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".
>
>
>