How to read a field Oracle containing XML - sql

Question

A table exists in the environment of production with the following structure:
CREATE TABLE gold_dwh_reload (
msisdn NUMBER(13,0) NOT NULL,
recharge_date TIMESTAMP(6) NOT NULL,
impacted_balances VARCHAR2(4000) NULL,
lc_state VARCHAR2(5) NOT NULL)
TABLESPACE sopfun_tab
NOCOMPRESS
/
A normal consultation would the following result by example:
MSISDN RECHARGE_DATE IMPACTED_BALANCES LC_STATE
584124723950 29.04.15 13:23:38.000 <balance><name>B_LPP_Bs_Main</name><label></label><before>697.21429</before><after>797.21429</after><amount>100</amount><start></start><end></end><unit>Bs</unit></balance><balance><name>B_LPP_KB_National</name><label>PA_Adjustment</label><before>0</before><after>10240</after><amount>10240</amount><start>29042015000000</start><end>29052015000000</end><unit>Kbytes</unit></balance><balance><name>B_LSP_Bs_Promotions</name><label>PA_Adjustment</label><before>0</before><after>25</after><amount>25</amount><start>29042015000000</start><end>29052015000000</end><unit>Bs</unit></balance> ACT
But i need to break the IMPACTED_BALANCES field in columns. Anyone know how I do it?

Answer 1

This is typically done using XMLTable
select
msisdn, recharge_date,
x_name, x_label, x_before, x_after, x_amount,
to_date(x_start, 'DDMMYYYYHH24MISS') x_start,
to_date(x_end, 'DDMMYYYYHH24MISS') x_end,
x_unit,
lc_state
from gold_dwh_reload
cross join
xmltable('/balances/balance'
passing xmltype('<balances>'||impacted_balances||'</balances>')
columns
x_name path '/balance/name',
x_label path '/balance/label',
x_before number path '/balance/before',
x_after number path '/balance/after',
x_amount number path '/balance/amount',
x_start path '/balance/start',
x_end path '/balance/end',
x_unit path '/balance/unit'
);
Here's a SQL Fiddle.
Mixing SQL and XML is powerful but creates many potential type safety issues. A single invalid date, number, or XML file will crash the whole query. The string in your example is not valid XML, that's why I concatenated another tag to the beginning and end.