Having RETURN issue in PLPGSQL - plpgsql

Question

I have created this store procedure to return a row_version if the organization id is in the database.
CREATE OR REPLACE FUNCTION sote.validate_row_version(a BIGINT, b BIGINT)
RETURNS text AS $$
DECLARE
ret RECORD;
v_error_stack text;
BEGIN
SELECT row_version INTO ret
FROM sote.organizations
WHERE organization_id = a;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RAISE EXCEPTION 'Organization Id (%) was not found', myOrganizationID;
GET STACKED DIAGNOSTICS v_error_stack = PG_EXCEPTION_CONTEXT;
RETURN to_json(v_error_stack);
RETURN '0';
END;$$ LANGUAGE plpgsql;
When I run this command,
SELECT sote.validate_row_version(2,4);
I get the following error. I don't understand why. Any help would be great.
ERROR: control reached end of function without RETURN

Answer 1

There are 2 problems:
your select statement will not raise an exception unless you specify SELECT ... INTO STRICT
your RETURN '0' statement is part of the exception handler and will never be executed.
So you can rewrite your function as
CREATE OR REPLACE FUNCTION sote.validate_row_version(a BIGINT, b BIGINT)
RETURNS text AS $$
DECLARE
ret RECORD;
v_error_stack text;
BEGIN
SELECT row_version INTO STRICT ret
FROM sote.organizations
WHERE organization_id = a;
RETURN '0';
EXCEPTION
WHEN NO_DATA_FOUND THEN
RAISE EXCEPTION 'Organization Id (%) was not found', myOrganizationID;
GET STACKED DIAGNOSTICS v_error_stack = PG_EXCEPTION_CONTEXT;
RETURN to_json(v_error_stack);
END;$$ LANGUAGE plpgsql;

Answer 2

You need to move the RETURN '0' so it's executed before the EXCEPTION handler:
CREATE OR REPLACE FUNCTION sote.validate_row_version(a BIGINT, b BIGINT)
RETURNS text AS $$
DECLARE
ret RECORD;
v_error_stack text;
BEGIN
SELECT row_version INTO ret
FROM sote.organizations
WHERE organization_id = a;
RETURN '0';
EXCEPTION
WHEN NO_DATA_FOUND THEN
RAISE EXCEPTION 'Organization Id (%) was not found', myOrganizationID;
GET STACKED DIAGNOSTICS v_error_stack = PG_EXCEPTION_CONTEXT;
RETURN to_json(v_error_stack);
END;$$ LANGUAGE plpgsql;
The code below EXCEPTION is all part of the exception block and won't be executed unless an exception occurs.
Best of luck.