How to update a part of JSON string in Oracle 12c? - json

Question

I've a table in my oracle DB as below.
CREATE TABLE my_table(
id RAW(16) NOT NULL,
data CLOB,
CONSTRAINT my_table_pk PRIMARY KEY (id),
CONSTRAINT my_table_json_chk CHECK (data IS JSON)
);
INSERT INTO my_table (id, data)
VALUES (SYS_GUID(),
'{
"FirstName" : "aa",
"LastName" : "bb",
"Address" : {
"Street" : "99 My Street",
"City" : "My City",
"Country" : "UK",
"Postcode" : "A12 34B"
}');
Now I know, I can fetch value of a specific property like address of the JSON string using $.
Similarly, can I update Street property of the JSON string without providing the entire JSON structure in my update query?
Please help me on this.

Answer 1

This is supported via PL/SQL in 12.2.0.1.0. New PL/SQL objects enable fine grained manipulation of JSON content
JSON_OBJECT_T: for working with JSON objects
JSON_ARRAY_T: for working with JSON Arrays
JSON_OBJECT_T and JSON_ARRAY_T are subtypes of JSON_ELEMENT_T
These objects provide a set of methods for manipulating JSON similar to GSON.
enter code here
WITH FUNCTION updateTax(JSON_DOC in VARCHAR2 ) RETURN VARCHAR2
IS
jo JSON_OBJECT_T;
price NUMBER;
taxRate NUMBER;
BEGIN
jo := JSON_OBJECT_T(JSON_DOC);
taxRate := jo.get_Number('taxRate');
price := jo.get_Number('total');
jo.put('totalIncludingTax', price * (1+taxRate));
RETURN jo.to_string();
END;
ORDERS as (
select '{"taxRate":0.175,"total":10.00}' JSON_DOCUMENT
from dual
)
select JSON_DOCUMENT, updateTax(JSON_DOCUMENT)
from ORDERS;
JSON_DOCUMENT UPDATETAX(JSON_DOCUMENT)
------------------------------- --------------------------------------------------------
{"taxRate":0.175,"total":10.00} {"taxRate":0.175,"total":10.00,"totalIncludingTax":11.75}
https://docs.oracle.com/database/122/ADJSN/using-PLSQL-object-types-for-JSON.htm#ADJSN-GUID-F0561593-D0B9-44EA-9C8C-ACB6AA9474EE