How to parse data inside CDATA in oracle - sql

Question

There is a column in the table with type CLOB and it stores the payloads.
I need to get the value with respect to tenantId (7 in this case). How do write a query to get the same. Can't use substr or instr since the order of tenantId changes from record to record.
<PayLoad><![CDATA[{"order":{"entityErrors":[],"action":"CONFIRM","tenantId":"7","Id":"2","deliveryReservationDetails":[{"reservationId":"c05e0c77-1c8f-4dce-a388-fe97fd36f96e","fulfillmentLocationType":"Store"}]}}]]></PayLoad>

Answer 1

In Oracle 12 you should be able to do:
SELECT tenantId
FROM your_table t
LEFT OUTER JOIN
XMLTABLE(
'/PayLoad/.'
PASSING XMLTYPE( t.your_xml_column )
COLUMNS cdata CLOB PATH '.'
) x
ON ( 1 = 1 )
LEFT OUTER JOIN
JSON_TABLE(
x.cdata,
'$'
COLUMNS ( tenantId VARCHAR2(10) PATH '$.order.tenantId' )
) j
ON ( 1 = 1 );
(Untested as I'm on 11g for the next few hours)
On Oracle 11:
SELECT REGEXP_SUBSTR( x.cdata, '"tenantId":"((\\"|[^"])*)"', 1, 1, NULL, 1 ) AS tenantId
FROM your_table t
LEFT OUTER JOIN
XMLTABLE(
'/PayLoad/.'
PASSING XMLTYPE( t.your_xml_column )
COLUMNS cdata CLOB PATH '.'
) x
ON ( 1 = 1 )
Or (if the JSON string will not occur in another branch of the XML) you could just use:
SELECT REGEXP_SUBSTR(
your_xml_column,
'"tenantId":"((\\"|[^"])*)"',
1,
1,
NULL,
1
) AS tenantId
FROM your_table

Answer 2

Your CDATA payload appears to be JSON, so if you're on 12c and only have one order per CDATA you can do:
select json_value(x.cdata, '$.order.tenantId' returning number) as tenantid
from your_table t
cross join xmltable('/PayLoad'
passing xmltype(your_clob)
columns cdata clob path './text()'
) x;
As #MTO pointed out, treating the JSON value as a number may not be valid, as it's shown as a string in the raw JSON. Making it returning varchar2(10) or some other suitable size may be more appropriate (and safer, at least until you use it).
Quick demo with your XML as a CTE:
with your_table (your_clob) as (
select to_clob('<PayLoad><![CDATA[{"order":{"entityErrors":[],"action":"CONFIRM","tenantId":"7","Id":"2","deliveryReservationDetails":[{"reservationId":"c05e0c77-1c8f-4dce-a388-fe97fd36f96e","fulfillmentLocationType":"Store"}]}}]]></PayLoad>') from dual
)
select json_value(x.cdata, '$.order.tenantId' returning number) as tenantid
from your_table t
cross join xmltable('/PayLoad'
passing xmltype(your_clob)
columns cdata clob path './text()'
) x;
TENANTID
----------------------
7