ORACLE SQL function to return JSON response - sql

Question

I have table like below. I am trying to pull all BRKPK_CNTNR_ID, SSP_Q with respect to each OVRPK_CNTNR_ID
enter image description here
Below query runs fine and produces desired result.
DECLARE
json_objects JSON_OBJECT_LIST := JSON_OBJECT_LIST() ;
counter NUMBER := 1;
BEGIN
FOR ovrpk_detail IN (SELECT OVRPK_CNTNR_ID ,BRKPK_CNTNR_ID,ITEM_DISTB_Q FROM OVRPK_DET od WHERE od.OVRPK_CNTNR_ID='92000000356873110552') LOOP
begin
json_objects.extend;
json_objects(counter) :=JSON_UTIL.JSON_OBJECT(
JSON_ATTRIBUTE_LIST(
JSON_UTIL.JSON_ATTRIBUTE('over_pack_container_id',ovrpk_detail.OVRPK_CNTNR_ID),
JSON_UTIL.JSON_ATTRIBUTE('break_pack_container_id',ovrpk_detail.BRKPK_CNTNR_ID),
JSON_UTIL.JSON_ATTRIBUTE('item_distributed_quantity',ovrpk_detail.ITEM_DISTB_Q)
));
counter := counter+1;
END;
END LOOP;
dbms_output.put_line( JSON_UTIL.JSON_ARRAY(json_objects));
END;
I am expecting is to create function that takes OVRPK_CNTNR_ID as input and returns JSON_OBJECT_LIST as output.
Here is my query I tried.
CREATE OR REPLACE FUNCTION get_json_objects(ovrk_cntnr_id IN CHAR)
RETURN JSON_OBJECT_LIST IS
json_objects JSON_OBJECT_LIST := JSON_OBJECT_LIST();
BEGIN
DECLARE counter NUMBER := 1;
FOR ovrpk_detail IN (SELECT OVRPK_CNTNR_ID ,BRKPK_CNTNR_ID FROM OVRPK_DET od WHERE od.OVRPK_CNTNR_ID= ovrk_cntnr_id) LOOP
begin
json_objects.extend;
json_objects(counter) :=JSON_UTIL.JSON_OBJECT(
JSON_ATTRIBUTE_LIST(
JSON_UTIL.JSON_ATTRIBUTE('over_pack_container_id',ovrpk_detail.OVRPK_CNTNR_ID),
JSON_UTIL.JSON_ATTRIBUTE('break_pack_container_id',ovrpk_detail.BRKPK_CNTNR_ID)
));
counter := counter+1;
END;
END LOOP;
RETURN json_objects;
END;
DECLARE
json_return_object JSON_OBJECT_LIST;
ovrk_cnt_i char := '92000000356873110552'
BEGIN
json_return_object := get_json_objects(ovrk_cnt_i);
dbms_output.put_line('JSON Object is: ' || json_return_object);
END;
I am missing something, would anyone help me to resolve this issue? Thank you
Note: I am using Oracle 12.c database which does not support JSON however, JSON_UTIL is library written internally to address same

Answer 1

We do not have your packages or functions so this is difficult to test.
Your code has a DECLARE without a corresponding BEGIN or END. If you get rid of all the unnecessary DECLARE/BEGIN/END statements then you can simplify it to:
CREATE OR REPLACE FUNCTION get_json_objects(
ovrk_cntnr_id IN CHAR
)
RETURN JSON_OBJECT_LIST
IS
json_objects JSON_OBJECT_LIST := JSON_OBJECT_LIST();
counter NUMBER := 1;
BEGIN
FOR ovrpk_detail IN (
SELECT OVRPK_CNTNR_ID,
BRKPK_CNTNR_ID
FROM OVRPK_DET
WHERE OVRPK_CNTNR_ID = ovrk_cntnr_id
) LOOP
json_objects.extend;
json_objects(counter) :=JSON_UTIL.JSON_OBJECT(
JSON_ATTRIBUTE_LIST(
JSON_UTIL.JSON_ATTRIBUTE('over_pack_container_id',ovrpk_detail.OVRPK_CNTNR_ID),
JSON_UTIL.JSON_ATTRIBUTE('break_pack_container_id',ovrpk_detail.BRKPK_CNTNR_ID)
)
);
counter := counter+1;
END LOOP;
RETURN json_objects;
END;
/
If your package functions are callable from SQL then you should be able to simplify it further to:
CREATE OR REPLACE FUNCTION get_json_objects(
i_ovrpk_cntnr_id IN OVRPK_DET.OVRPK_CNTNR_ID%TYPE
) RETURN JSON_OBJECT_LIST
IS
json_objects JSON_OBJECT_LIST;
BEGIN
SELECT JSON_UTIL.JSON_OBJECT(
JSON_ATTRIBUTE_LIST(
JSON_UTIL.JSON_ATTRIBUTE('over_pack_container_id', OVRPK_CNTNR_ID),
JSON_UTIL.JSON_ATTRIBUTE('break_pack_container_id', BRKPK_CNTNR_ID)
)
)
BULK COLLECT INTO json_objects
FROM OVRPK_DET
WHERE OVRPK_CNTNR_ID = i_ovrpk_cntnr_id;
RETURN json_objects;
END;
/
DECLARE
json_return_object JSON_OBJECT_LIST;
ovrk_cnt_i OVRPK_DET.OVRPK_CNTNR_ID%TYPE := '92000000356873110552'
BEGIN
json_return_object := get_json_objects(ovrk_cnt_i);
dbms_output.put_line('JSON Object is: ' || json_return_object);
END;
/