query json array with Oracle 12cR2 json features - json

Question

I am using Oracle (12cR2) json but couldn't find a way to query arrays containing certain elements. Here is the test code:
CREATE TABLE json_array (
id NUMBER NOT NULL,
array CLOB,
CONSTRAINT json_array_pk PRIMARY KEY (id),
CONSTRAINT json_array_chk_1 CHECK (array IS JSON)
);
INSERT INTO json_array (id, array) VALUES (1, '{"a":[1, 3]}');
INSERT INTO json_array (id, array) VALUES (2, '{"a":[2, 4, 6]}');
INSERT INTO json_array (id, array) VALUES (3, '{"a":[1, 2, 5]}');
INSERT INTO json_array (id, array) VALUES (4, '{"a":[2, 5]}');
INSERT INTO json_array (id, array) VALUES (5, '{"a":[5]}');
INSERT INTO json_array (id, array) VALUES (6, '{"a":[5, 2]}');
COMMIT;
Create a domain index:
CREATE SEARCH INDEX idx_json_array ON json_array (array) FOR JSON;
I want to find all rows containing the array element 2 and 5, regardless their order in the array, i.e. the SQL should return the rows with id 3, 4, 6.
I tried many options:
SQL1:
select * from json_array j -- return any arrays containing 2
where json_exists(j.array, '$?(#.a[0] == 2)');
==> return the rows containing 2: id = 2, 3, 4, 6
SQL2:
select * from json_array j -- return arrays containing 2 at index 1
where json_exists(j.array, '$?(#.a[0] == 2 || #.a[0] == 5)');
==> return rows containing 2 or 5: id = 2, 4, 5, 6
SQL3:
select * from json_array j -- return arrays containing 2 at index 1
where json_exists(j.array, '$?(#.a[0] == 2 && #.a[0] == 5)');
==> return no row
SQL4:
select * from json_array j -- returns arrays containing 2 OR 5
where json_textcontains(j.array, '$.a', '[2,5]');
==> return rows containing 2 or 5: id = 2, 3, 4, 5, 6
SQL5:
select * from json_array j
where json_textcontains(j.array, '$.a', '{[2] & [5]}');
==> returns rows containing 2 AND 5, with 2 preceding 5
The only SQL that returns what I want is:
SQL6:
select * from json_array j
where json_textcontains(j.array, '$.a', '[2]') AND json_textcontains(j.array, '$.a', '[5]');
==> returns id = 3, 4, 6
But this solution can be very cumbersome when the number of elements increases.
Question: are there better option that SQL6 to return the same results?
Oracle version for testing 12c R2
Thanks in advance
James

Answer 1

Does this help...
SQL> with MY_TABLE as
2 (
3 select 1 as ID, '{"a":[1, 3]}' as ARRAY
4 from DUAL
5 union all
6 select 2 as ID, '{"a":[2, 4, 6]}' as ARRAY
7 from DUAL
8 union all
9 select 3 as ID, '{"a":[1, 2, 5]}' as ARRAY
10 from DUAL
11 union all
12 select 4 as ID, '{"a":[2, 5]}' as ARRAY
13 from DUAL
14 union all
15 select 5 as ID, '{"a":[5]}' as ARRAY
16 from DUAL
17 union all
18 select 6 as ID, '{"a":[5, 2]}' as ARRAY
19 from DUAL
20 )
21 select ID
22 from MY_TABLE
23 where json_exists(ARRAY,'$?(#.a == 2 && #.a == 5)')
24 /
ID
----------
3
4
6
SQL>