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, converting it from ISO to UTF-8 with iconv and exporting to json with json_encode. The whole operation takes about 1 second on DB side and 5 seconds to generate JSON. It is way to long.

The question

I have read that Oracle 12c supports JSON, but I cannot find exactly what I need.

Is there a way to return the result of a standard sql query in a json format?

supposedly I would like to issue a query similar to this:

SELECT * from table AS JSON

and receive a valid json similar to this:

[{"col1": "value1", "col2": 2}, {"col1": "valueOfRow2", "col2": 3}]

An important thing is that I need to have the unicode sequences escaped for me, as I use ISO-8859-2 charset on the client side, and JSON have to be in either UTF-8 or have the sequences escaped.

Answer 1

Oracle 12c version 12.1.0.2 (the latest version as of 11.11.2014) adds JSON support: https://docs.oracle.com/database/121/NEWFT/chapter12102.htm#BGBGADCC

It's been available since October 17th. https://blogs.oracle.com/db/entry/oracle_database_12c_release_1

If you are unable to patch/work with that version there is an excellent package written by Lewis Cunningham and Jonas Krogsboell: PL/JSON * http://pljson.sourceforge.net/

It's an excellent package (I have used it in numerous database installations).

The examples included are good and cover most scenarios.

declare 
  ret json;
begin
  ret := json_dyn.executeObject('select * from tab');
  ret.print;
end;
/