SQL & PL/SQL

Hi,

I'm trying to generate json data using json_object_t  datatype and inserting into it.   I have created a samle scenario here  and it is giving me the error

Database version is 12cR2.

Error report -

ORA-40573: Invalid use of PL/SQL JSON object type.

ORA-06512: at line 5

create table s1 ( s varchar2(32767));

alter table "ADPDBT"."S1" add constraint SCK check(S IS JSON) ENABLE;

inserting data into the table

                             DECLARE

                                  r_js    json_object_t;

                              BEGIN                                                              

                                    r_js := JSON_OBJECT_T('{ "employee_no":9999 }');

                                    insert into s1 values (r_js.to_string);

                                    commit;

                            END;

                            /

Regards,

hsemar