Re: Opening view that uses a function - empty column

Oh! And, I made another observation while cracking away at this: When I connect to the DB using PGAdmin (1.14.3) from a remote workstation as opposed to on the DB server itself, I see the same problem with the empty external_id column when executing "select * from rhs.encounter;".

Could this be a problem with how I have implemented my functions? There are two functions calls actually used to fill the column - I included the complete text of the functions below.

get_valid_xml - ensures that content from pg_largeobject is valid xml
extract_from_extended - uses xmlparse and xpath to get one specific value

Thanks...again!

/* Function to validate xml for xpath use in SQL query */
CREATE OR REPLACE FUNCTION rhs.get_valid_xml(x text)
RETURNS xml AS
$BODY$
BEGIN
PERFORM XMLPARSE( DOCUMENT x );
RETURN XMLPARSE( DOCUMENT x );
EXCEPTION WHEN OTHERS THEN
RETURN XMLPARSE( DOCUMENT '<?xml version="1.0" encoding="UTF-8"?><fields></fields>' );
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION rhs.get_valid_xml(text) OWNER TO postgres;

/* Function to allow extract of fields from _extended */
CREATE OR REPLACE FUNCTION rhs.extract_from_extended(field_name text, menu_data_id bigint)
RETURNS text AS
$BODY$
select translate( xpath('//field[(at)name="'||$1||'" and @type="String"]/text()', xmlparse(document ( rhs.get_valid_xml( array_to_string( array(select lo.data from app.menu_data md, pg_catalog.pg_largeobject lo where md.id = $2 and md.xml01 = lo.loid), '') ) )))::text, '{}', '');
$BODY$
LANGUAGE sql VOLATILE
COST 100;
ALTER FUNCTION rhs.extract_from_extended(text, bigint) OWNER TO postgres;

On Friday, July 27, 2012 1:46:20 PM UTC-6, Brady Mathis wrote:
> Two step inquiry:
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> 1) I have created a function that will parse a value out of XML stored in the pg_largeobject table using xpath, like so:
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> CREATE OR REPLACE FUNCTION extract_from_extended(text, bigint)
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> RETURNS text AS
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> $BODY$
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> select translate( xpath(...) );
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> $BODY$
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> LANGUAGE sql VOLATILE
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> COST 100;
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> 2) I then created a view that calls this function as part of the query, like so:
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> CREATE OR REPLACE VIEW encounter AS
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> SELECT md.account_id, extract_from_extended('externalEncounterID'::text, md.id) AS external_id...
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> FROM app.menu_data md, app.menu_structure ms
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> WHERE...;
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>
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> When I open this view via JDBC, there is no data in the column that is filled by the function call.
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> Any thoughts?
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> TIA,
>
> BRady