JSON is suddenly the most popular thing since sliced bread. This mini-lesson shows some of the new JSON handling capabilities in Oracle 12c Release 1

1. 1
12c

2. 2
the focus ...
the day to day stuff

3. Feature
JSON

4. <department name="ACCOUNTING">
<employees>
<employee>
<ename>KING</ename>
<job>PRESIDENT</job>
<sal>5000</sal>
</employee>
<employee>
<ename>MILLER</ename>
<job>CLERK</job>
<sal>1300</sal>
</employee>
</employees>
</department>

5. { "NAME" :"ACCOUNTING"
, "EMPLOYEES" : [
{"ENAME" : "KING",
"JOB" : "PRESIDENT",
"SAL" : 5000
},
{"ENAME" : "MILLER",
"JOB" : "CLERK",
"SAL" : 1300
}]
}

6. { Name : Value }

7. {
Name : Value,
Name : Value,
Name : Value
}

8. {
{
Name : Value,
Name : Value,
Name : Value
}
,
{
Name : Value,
Name : Value,
Name : Value
}
}

9. create table T
( id number(10),
my_doc varchar2(4000)
)

10. alter table T
add constraint t_chk
check
(
my_doc is JSON
)

11. insert into T
values (1,
'{ "Valid" : "json" }'
);

12. insert into T
values (2,
'some junk'
);
ORA-02290: check constraint (TABTCMC.T_CHK) violated

13. extraction

14. SQL> select json_value(my_doc,'$.Valid') tag
2 from t;
TAG
------
json

15. SQL> insert into T values (2,
2 '{ "ACCOUNTING" : {
3 "EMPLOYEES" : [
4 {"ENAME" : "KING",
5 "JOB" : "PRESIDENT",
6 "SAL" : 5000
7 },
8 {"ENAME" : "MILLER",
9 "JOB" : "CLERK",
10 "SAL" : 1300
11 }]
12 }
13 }');
1 row created.

16. SQL> select json_value(my_doc,
2 '$.ACCOUNTING.EMPLOYEES[0].ENAME') as ename
3 from t;
ENAME
----------
KING

17. SQL> select json_query(my_doc,
2 '$.*.EMPLOYEES') as result
3 from T
4 /
RESULT
---------
[{"ENAME":"KING","JOB":"PRESIDENT","SAL":5000},{"ENAME":
"MILLER","JOB":"CLERK","SAL":1300}]

18. SQL> select t.my_doc.ACCOUNTING.EMPLOYEES.ENAME emps,
2 t.my_doc.ACCOUNTING.EMPLOYEES.JOB jobs,
3 t.my_doc.ACCOUNTING.EMPLOYEES.SAL sals
4 from T t;
EMPS JOBS SALS
-------------------- ------------------- ---------------
[KING,MILLER] [PRESIDENT,CLERK] [5000,1300]

19. SQL> select ename, job, sal
2 from t,
3 json_table(my_doc,'$.ACCOUNTING.EMPLOYEES[*]'
4 columns(ename varchar2(20) path '$.ENAME',
5 job varchar2(20) path '$.JOB',
6 sal number path '$.SAL'
7 ));
ENAME JOB SAL
-------------------- -------------------- ----------
KING PRESIDENT 5000
MILLER CLERK 1300

20. searching

21. SQL> select count(*)
2 from T
3 where json_exists(my_doc,'$.*.EMPLOYEES');
COUNT(*)
----------
1
SQL> select count(*)
2 from T
3 where my_doc is json;
COUNT(*)
----------
1