Cannot run Postgres Stored Procedure [duplicate] - postgresql

Question

I have a Postgres function which is returning a table:
CREATE OR REPLACE FUNCTION testFunction() RETURNS TABLE(a int, b int) AS
$BODY$
DECLARE a int DEFAULT 0;
DECLARE b int DEFAULT 0;
BEGIN
CREATE TABLE tempTable AS SELECT a, b;
RETURN QUERY SELECT * FROM tempTable;
DROP TABLE tempTable;
END;
$BODY$
LANGUAGE plpgsql;
This function is not returning data in row and column form. Instead it returns data as:
(0,0)
That is causing a problem in Coldfusion cfquery block in extracting data. How do I get data in rows and columns when a table is returned from this function? In other words: Why does the PL/pgSQL function not return data as columns?

Answer 1

To get individual columns instead of the row type, call the function with:
SELECT * FROM testfunction();
Just like you would select all columns from a table.
Also consider this reviewed form of your test function:
CREATE OR REPLACE FUNCTION testfunction()
RETURNS TABLE(a int, b int)
LANGUAGE plpgsql AS
$func$
DECLARE
_a int := 0;
_b int := 0;
BEGIN
CREATE TABLE tempTable AS SELECT _a, _b;
RETURN QUERY SELECT * FROM tempTable;
DROP TABLE tempTable;
END
$func$;
In particular:
The DECLARE key word is only needed once.
Avoid declaring parameters that are already (implicitly) declared as OUT parameters in the RETURNS TABLE (...) clause.
Don't use unquoted CaMeL-case identifiers in Postgres. It works, unquoted identifiers are cast to lower case, but it can lead to confusing errors. See:
Are PostgreSQL column names case-sensitive?
The temporary table in the example is completely useless (probably over-simplified). The example as given boils down to:
CREATE OR REPLACE FUNCTION testfunction(OUT a int, OUT b int)
LANGUAGE plpgsql AS
$func$
BEGIN
a := 0;
b := 0;
END
$func$;

Answer 2

Of course you can do this by putting the function call in the FROM clause, like Eric Brandstetter correctly answered.
However, this is sometimes complicating in a query that already has other things in the FROM clause.
To get the individual columns that the function returns, you can use this syntax:
SELECT (testfunction()).*
Or to get only the column called "a":
SELECT (testfunction()).a
Place the whole function, including the input value(s) in parenteses, followed by a dot and the desired column name, or an asterisk.
To get the column names that the function returns, you'll have to either:
check the source code
inspect the result of the function first, like so : SELECT * FROM testfunction() .
The input values can still come out of a FROM clause.
Just to illustrate this, consider this function and test data:
CREATE FUNCTION funky(a integer, b integer)
RETURNS TABLE(x double precision, y double precision) AS $$
SELECT a*random(), b*random();
$$ LANGUAGE SQL;
CREATE TABLE mytable(a integer, b integer);
INSERT INTO mytable
SELECT generate_series(1,100), generate_series(101,200);
You could call the function "funky(a,b)", without the need to put it in the FROM clause:
SELECT (funky(mytable.a, mytable.b)).*
FROM mytable;
Which would result in 2 columns:
x | y
-------------------+-------------------
0.202419687062502 | 55.417385618668
1.97231830470264 | 63.3628275180236
1.89781916560605 | 1.98870931006968
(...)