Is there any way to obtain a table with key/value pairs from a CLOB Json Column?
The idea here is to get these values, on a dynamic way. Because the CLOB column does not always contain the same structure.
I've created a function that does this, however since it literally parses the json string, when we use it in a table with many records its very slow. And by very slow I mean like 2-5 records per second, i know it's terrible.
The Oracle tools (v.12c) do not provide a dynamic way to obtain the json tags/values, we have always to specify the paths.
I've been digging all around without any luck. Any thoughts?
12.2 contains a set of PL/SQL objects that can be used to build a DOM like structure of a JSON document. You can then extract key lists etc using methods on the objects. Look in the 12.2 doc for JSON_OBJECT_T, JSON_ARRAY_T etc which can be used like this..
SQL> create or replace type NV_PAIR_T as object (
2 NAME VARCHAR2(32),
3 VALUE VARCHAR2(32)
4 )
5 /
Type created.
SQL> create or replace type NV_PAIR_TABLE as TABLE of NV_PAIR_T
2 /
Type created.
SQL> create or replace function GET_KEY_VALUES(P_JSON_DOC VARCHAR2)
2 return NV_PAIR_TABLE PIPELINED
3 as
4 JO JSON_OBJECT_T := JSON_OBJECT_T(P_JSON_DOC);
5 JO_KEYS JSON_KEY_LIST := JO.get_keys();
6 begin
7
8 for i in 1..JO_KEYS.count loop
9 pipe row (NV_PAIR_T(JO_KEYS(i),JO.get_string(JO_KEYS(i))));
10 end loop;
11 end;
12 /
Function created.
SQL> select *
2 from TABLE(GET_KEY_VALUES('{"A":"AA", "B":"BB", "C":"CC"}'))
3 /
A AA
B BB
C CC
SQL>
Does this help