Generate JSON Structure looping over table in Oracle SQL - sql

Question

I have ORACLE-SQL Table in below format.
Version is Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit
CREATE TABLE temp_Table
(
"OVRPK_CNTNR_ID" CHAR(20) NOT NULL ENABLE,
"ITEM_DISTB_Q" NUMBER(3) NOT NULL ENABLE,
"SSP_Q" NUMBER(6,0) NOT NULL ENABLE,
"BRKPK_CNTNR_ID" CHAR(20)
) ;
INSERT INTO temp_Table (OVRPK_CNTNR_ID, ITEM_DISTB_Q, SSP_Q, BRKPK_CNTNR_ID ) VALUES('92000000356873110552', 6,8,'93058901021076000085');
INSERT INTO temp_Table (OVRPK_CNTNR_ID,ITEM_DISTB_Q,SSP_Q, BRKPK_CNTNR_ID ) VALUES('92000000356873110552',8, 10,'93058901021117700080');
INSERT INTO temp_Table (OVRPK_CNTNR_ID,ITEM_DISTB_Q,SSP_Q, BRKPK_CNTNR_ID ) VALUES('92000000356873110552', 10,2,'93058901022276900083');
INSERT INTO temp_Table (OVRPK_CNTNR_ID,ITEM_DISTB_Q,SSP_Q, BRKPK_CNTNR_ID ) VALUES('92000000334160826089', 3,4,'000000000083465239');
INSERT INTO temp_Table (OVRPK_CNTNR_ID,ITEM_DISTB_Q,SSP_Q, BRKPK_CNTNR_ID ) VALUES('92000000334160826089', 3,4,'000000000083438160');
I have written trigger for above table.
AFTER INSERT OR DELETE OR UPDATE OF
OVRPK_CNTNR_ID, ITEM_DISTB_Q, SSP_Q, BRKPK_CNTNR_ID
ON
temp_Table
FOR EACH ROW
DECLARE
json_message CLOB := '';
BEGIN
/*
* pick OVRPK_CNTNR_ID from triggers row and send it to function createJson() return json object, example : 92000000356873110552
*/
json_message = CALL FUNCTION createJson(:NEW.OVRPK_CNTNR_ID);
END;
CREATE OR REPLACE FUNCTION createJson(ovrpk_container_id IN char)
BEGIN
SELECT json_query(
json_objectagg(OVRPK_CNTNR_ID value
json_array(
json_object("break_pack_container_id" VALUE BRKPK_CNTNR_ID,
"ssp_quantity" VALUE SSP_Q,
"item_distribution_quantity" VALUE ITEM_DISTB_Q)))),
'$' returning VARCHAR2(4000) pretty )
AS "Result JSON"
FROM temp_Table
END;
I am trying to create OUTPUT like below: but oracle version is Database 12c. I am not sure if it supports.
{
"Over_pack_container_id":"92000000356873110552"
"type": "OVER_PACK",
"sub_containers": [
{
"break_pack_container_id": "93058901021076000085",
"ssp_quantity": 8,
"item_distribution_quantity": 6
},
{
"break_pack_container_id": "93058901021117700080",
"ssp_quantity": 10,
"item_distribution_quantity": 8
},
{
"break_pack_container_id": "93058901022276900083",
"ssp_quantity": 2,
"item_distribution_quantity": 10
}
]
}
can someone help me here? Thank you

Answer 1

It is unclear what you are trying to achieve with the trigger or the function because the trigger does not do anything.
However, you can get your JSON output format using:
SELECT JSON_OBJECT(
KEY 'Over_pack_container_id' VALUE OVRPK_CNTNR_ID,
KEY 'type' VALUE 'OVER_PACK',
KEY 'sub_containers' VALUE JSON_ARRAYAGG(
JSON_OBJECT(
KEY 'break_pack_container_id' VALUE BRKPK_CNTNR_ID,
KEY 'ssp_quantity' VALUE SSP_Q,
KEY 'item_distribution_quantity' VALUE ITEM_DISTB_Q
)
)
) AS "Result JSON"
FROM temp_Table
GROUP BY OVRPK_CNTNR_ID;
Which, for the sample data, outputs:
Result JSON
{"Over_pack_container_id":"92000000334160826089","type":"OVER_PACK","sub_containers":[{"break_pack_container_id":"000000000083465239 ","ssp_quantity":4,"item_distribution_quantity":3},{"break_pack_container_id":"000000000083438160 ","ssp_quantity":4,"item_distribution_quantity":3}]}
{"Over_pack_container_id":"92000000356873110552","type":"OVER_PACK","sub_containers":[{"break_pack_container_id":"93058901021076000085","ssp_quantity":8,"item_distribution_quantity":6},{"break_pack_container_id":"93058901022276900083","ssp_quantity":2,"item_distribution_quantity":10},{"break_pack_container_id":"93058901021117700080","ssp_quantity":10,"item_distribution_quantity":8}]}
If you only want a single container ID in your function then use a where clause:
SELECT JSON_OBJECT(
KEY 'Over_pack_container_id' VALUE OVRPK_CNTNR_ID,
KEY 'type' VALUE 'OVER_PACK',
KEY 'sub_containers' VALUE JSON_ARRAYAGG(
JSON_OBJECT(
KEY 'break_pack_container_id' VALUE BRKPK_CNTNR_ID,
KEY 'ssp_quantity' VALUE SSP_Q,
KEY 'item_distribution_quantity' VALUE ITEM_DISTB_Q
)
)
) AS "Result JSON"
FROM temp_Table
WHERE OVRPK_CNTNR_ID = ovrpk_container_id
GROUP BY OVRPK_CNTNR_ID;
If you want to do it on a version before the JSON functions were introduced then you can use LISTAGG (from Oracle 11 and provided you are not generating more than 4000 byte strings):
SELECT '{'
|| '"Over_pack_container_id":"' || OVRPK_CNTNR_ID || '",'
|| '"type":"OVER_PACK",'
|| '"sub_containers":['
|| LISTAGG(
'{'
|| '"break_pack_container_id":"' || BRKPK_CNTNR_ID || '"'
|| '"ssp_quantity":' || COALESCE(TO_CHAR(SSP_Q), 'null')
|| '"item_distribution_quantity":' || COALESCE(TO_CHAR(ITEM_DISTB_Q), 'null')
|| '}',
','
) WITHIN GROUP (ORDER BY BRKPK_CNTNR_ID)
|| ']'
|| '}'
AS "Result JSON"
FROM temp_Table
GROUP BY OVRPK_CNTNR_ID;
fiddle