Return results of a sql query as JSON in oracle 12c

Question

Background

I need to fetch a few thousands rows from Oracle and convert them to JSON for use in SlickGrid. Currently I am fetching the rows in PHP,

Answer 1

Starting Oracle 19c, the syntax to construct a JSON representation for a row of a table is simplified

For Eg: To convert all the rows of the hr.employees to separate jsons, use

SELECT JSON_OBJECT(*) FROM hr.employees ;

{
"EMPLOYEE_ID" : 100,
"FIRST_NAME" : "Steven",
"LAST_NAME" : "King",
"EMAIL" : "SKING",
"PHONE_NUMBER" : "515.123.4567",
"HIRE_DATE" : "2003-06-17T00:00:00",
"JOB_ID" : "AD_PRES",
"SALARY" : 24000,
"COMMISSION_PCT" : null,
"MANAGER_ID" : null,
"DEPARTMENT_ID" : 90
}                       --row 1
{
"EMPLOYEE_ID" : 101,
"FIRST_NAME" : "Neena",
"LAST_NAME" : "Kochhar",
"EMAIL" : "NKOCHHAR",
"PHONE_NUMBER" : "515.123.4568",
"HIRE_DATE" : "2005-09-21T00:00:00",
"JOB_ID" : "AD_VP",
"SALARY" : 17000,
"COMMISSION_PCT" : null,
"MANAGER_ID" : 100,
"DEPARTMENT_ID" : 90
}                       --row 2
 ...

LIVE SQL example

Answer 2

To add to the answer in oracle 12.2 , you can create json as you want like this .

SELECT JSON_ARRAY(
JSON_OBJECT (
         KEY 'number' VALUE s.number,
         KEY 'name' VALUE s.sname,
         KEY 'location' VALUE s.loc
          )
       ) AS student_det
FROM   student s;

Answer 3

I do not see Python solution (in case you need to dump JSON).

I wrote json-ora-extract for medium size extracts (because data-set has to fit available memory).

It uses wx_Oracle and json Python modules to read data from Oracle data base (any version) and dump it into *.json file.

There's also an option to create compressed *.gz file.