How to make a join with the stored procedure result? - sql

Question

I want to make a join between a query and the result of stored procedure (for some reason).
my query is:
SELECT COUNT(a.values_key) AS docscount,b.main_code,b.year
FROM SP_name_should_be_here a
INNER JOIN dmr23req b
ON a.values_key = b.req_year || ',' || b.req_ser
AND a.newstateserial = 17
AND a.taskcode = 35
GROUP BY b.main_code,b.year
My stored procedure dmr_get_full_in takes two param

Answer 1

The answer is that you should use an 'iterator function' in the FROM clause:
FROM TABLE(FUNCTION stored_procedure(arg1, arg2)) AS alias(col1, col2, ....)
The 'alias' is not always necessary, but look hard at the column names in the output of executing the procedure directly:
EXECUTE stored_procedure(arg1, arg2)
If that contains unique column names, you'll be OK; if not, you won't and you'll need the AS alias(col1, col2, ...) notation.
Here's an analogue (more or less) to your query.
Trivial function that could be written differently, but works:
CREATE FUNCTION SimpleElements(lo INTEGER, hi INTEGER) RETURNING INTEGER AS Atomic_Number;
DEFINE an INTEGER;
FOREACH SELECT Atomic_Number
INTO an
FROM Elements
WHERE Atomic_Number BETWEEN lo AND hi
ORDER BY Atomic_Number
RETURN an WITH RESUME;
END FOREACH;
END FUNCTION;
Query using TABLE(FUNCTION stored_procedure(arg1, arg2)):
The MOD function is used as simple way of generating some groups to count, but it illustrates the notation which is the main point of the exercise.
SELECT COUNT(*) AS group_count, MOD(b.atomic_number, 3) AS mod_num
FROM TABLE(FUNCTION SimpleElements(1, 10)) AS a(Atomic_Number)
JOIN Elements AS b
ON a.atomic_number = b.atomic_number
GROUP BY mod_num
ORDER BY mod_num;
Output:
3 0
4 1
3 2
Table of Elements
CREATE TABLE elements
(
atomic_number INTEGER NOT NULL UNIQUE CONSTRAINT c1_elements
CHECK (atomic_number > 0 AND atomic_number < 120),
symbol CHAR(3) NOT NULL UNIQUE CONSTRAINT c2_elements,
name CHAR(20) NOT NULL UNIQUE CONSTRAINT c3_elements,
atomic_weight DECIMAL(8,4) NOT NULL,
stable CHAR(1) DEFAULT 'Y' NOT NULL
CHECK (stable IN ('Y', 'N'))
);
INSERT INTO elements VALUES( 1, 'H', 'Hydrogen', 1.0079, 'Y');
INSERT INTO elements VALUES( 2, 'He', 'Helium', 4.0026, 'Y');
INSERT INTO elements VALUES( 3, 'Li', 'Lithium', 6.9410, 'Y');
INSERT INTO elements VALUES( 4, 'Be', 'Beryllium', 9.0122, 'Y');
INSERT INTO elements VALUES( 5, 'B', 'Boron', 10.8110, 'Y');
INSERT INTO elements VALUES( 6, 'C', 'Carbon', 12.0110, 'Y');
INSERT INTO elements VALUES( 7, 'N', 'Nitrogen', 14.0070, 'Y');
INSERT INTO elements VALUES( 8, 'O', 'Oxygen', 15.9990, 'Y');
INSERT INTO elements VALUES( 9, 'F', 'Fluorine', 18.9980, 'Y');
INSERT INTO elements VALUES( 10, 'Ne', 'Neon', 20.1800, 'Y');
INSERT INTO elements VALUES( 11, 'Na', 'Sodium', 22.9900, 'Y');
INSERT INTO elements VALUES( 12, 'Mg', 'Magnesium', 24.3050, 'Y');
INSERT INTO elements VALUES( 13, 'Al', 'Aluminium', 26.9820, 'Y');
INSERT INTO elements VALUES( 14, 'Si', 'Silicon', 28.0860, 'Y');
INSERT INTO elements VALUES( 15, 'P', 'Phosphorus', 30.9740, 'Y');
INSERT INTO elements VALUES( 16, 'S', 'Sulphur', 32.0650, 'Y');
INSERT INTO elements VALUES( 17, 'Cl', 'Chlorine', 35.4530, 'Y');
INSERT INTO elements VALUES( 18, 'Ar', 'Argon', 39.9480, 'Y');
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