On 15/11/2011 12:45, Graham wrote:
> Using PG 9.0.3, I wish to dynamically reference a column in a table
> passed into a PL/PgSQL function as follows:
>
> -- A table with some values.
> DROP TABLE IF EXISTS table1;
> CREATE TABLE table1 (
> code INT,
> descr TEXT
> );
>
> INSERT INTO table1 VALUES ('1','a');
> INSERT INTO table1 VALUES ('2','b');
>
> -- The function code.
> DROP FUNCTION IF EXISTS foo (TEXT);
> CREATE FUNCTION foo (tbl_name TEXT) RETURNS VOID
>
> AS $$
> DECLARE
> r RECORD;
> d TEXT;
> BEGIN
> FOR r IN
> EXECUTE 'SELECT * FROM ' || tbl_name
> LOOP
> --SELECT r.descr INTO d; --IT WORK
> EXECUTE 'SELECT ($1)' || '.descr' INTO d USING r; --DOES NOT WORK
> RAISE NOTICE '%', d;
> END LOOP;
I think that everything after EXECUTE needs to be a string. Also, USING
is part of an ORDER BY clause; so you'd do:
EXECUTE 'SELECT ($1)' || '.descr INTO d ORDER BY whatever USING
some_operator';
Ray.
--
Raymond O'Donnell :: Galway :: Ireland
rod@xxxxxx
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