Get json with pljson & plsql - plsql

Question

I'm trying to chop out some lists from the following json using pljson
my_json := json('{"Order":
{"no": 1, "batch": 2,"id": 3,"quantity": 10,
"sm_pack": [
{
"no": 10,
"id": 1010,
"quantity": 2
},
{
"no": 11,
"id": 1040,
"quantity": 8
}
],
"sm_size": [
{ ....etc etc
However, I can't get it to work?
I can print the data using this syntax:
v_myjson.path('Order.sm_pack').print;
v_myjson.path('Order.sm_pack[1].no').print;
But how can I assing all those different lists to variables for further processing. i tried different versions of "v_list := json_list(my_json.get('Order.sm_pack')) .. my_json.get('sm_pack').. whatever I try its"NULL SELF" and I seem to have turned blind.
Regards

Answer 1

Printing json lists and objects differs from assigning them to some variables to manipulate them. I will try to answer your question through your example as follows:
DECLARE
obj json := json();
obj_1 json := json();
arr json_list := json_list();
val NUMBER;
BEGIN
/*Create your object*/
obj := json('{"Order":{"no":1,"batch":2,"id":3,"quantity":10,"sm_pack":[{"no":10,"id":1010,"quantity":2},{"no":11,"id":1040,"quantity":8}],"sm_size":[{"no":10,"id":1010,"quantity":2},{"no":11,"id":1040,"quantity":8}]}}');
/*Assign object*/
obj_1 :=json(obj.get('Order'));
/*Assign list from within the object*/
arr := json_list(obj_1.get('sm_pack'));
arr.print;
--or
arr := json_list(json(obj.get('Order')).get('sm_pack'));
arr.print;
/*Get object value from within list*/
val := json_ext.get_number(json(arr.get(2)), 'id');
DBMS_OUTPUT.PUT_LINE(VAL);
END;
/
Notice I used get_number function as your values without single quotes, otherwise, I would use get_string.
Hope that helps!