Oracle Database has the capability to store XML files. Oracle 9i onwards, there is a a datatype called XMLTYPE. Internally, Oracle uses CLOB to store the XML data. In this blog i will demonstrate how to load XML files to XMLTYPE table in Oracle Database and how to use query to extract data in tabular form.
1. Create a table with XMLTYPE column
create table XML_FILES
(
XMLDATA sys.XMLTYPE NOT NULL,
FILE_ID NUMBER (10) NOT NULL,
FILE_NAME VARCHAR2 (255) NOT NULL)
2. Load the XML files using SQL Loader.
a) Create a SQL Loader control file
Open notepad and add the below entries and save file as load_xml.ctl
load data
infile 'xml_files.dat'
into table XML_FILES append
fields terminated by ','
(
xml_filler filler char
,xmldata lobfile(xml_filler) terminated by EOF
,file_id
,file_name
)
b) Create data file xml_files.dat.
This file will be used by SQL Loader control file to read the file, filename and file id. Optionally, You can use shell script or batch programs to generate .dat file by reading directory. Structure of the file should look similar as shown below.
XMLFILE_AA_11.xml,1,'XMLFILE_AA_11.xml'
XMLFILE_AA_12.xml,2,'XMLFILE_AA_12.xml'
XMLFILE_AA_13.xml,3,'XMLFILE_AA_13.xml'
XMLFILE_AA_14.xml,4,'XMLFILE_AA_14.xml'
XMLFILE_AA_15.xml,5,'XMLFILE_AA_15.xml'
SAMPLE XML File content is shown below.
<?xml version="1.0" encoding="UTF-8"?>
<EMPDATA TIME_STAMP="2006-08-07T15:00:42"
TRANSACTION_ID="2006-08-07T15:00:42" VERSION="1.0">
<HEADER>
<SENDER>
<SENDER_NAME>XYZ Corp</SENDER_NAME>
</SENDER>
<RECEIVER>
<RECEIVER_NAME>ABC Bank</RECEIVER_NAME>
</RECEIVER>
</HEADER>
<BODY>
<EMP>
<EMPNUM>12345678</EMPNUM>
<DEPT>07I7</DEPT>
<LOCATION>22</LOCATION>
<HIRE_DATE>2006-08-07 00:12:00.0</HIRE_DATE>
<FIRST_NAME>JOHN</FIRST_NAME>
<LAST_NAME>SMITH</LAST_NAME>
<PHONES>
<PHONE type="Office">5676739</PHONE>
<PHONE type="Office">9123412432</PHONE>
</PHONES>
<AC_NO>12313-123123-1233</AC_NO>
<AMOUNT>2500.00</AMOUNT>
</EMP>
<EMP>
<EMPNUM>12345679</EMPNUM>
<DEPT>07I2</DEPT>
<LOCATION>22</LOCATION>
<HIRE_DATE>2006-08-17 00:12:00.0</HIRE_DATE>
<FIRST_NAME>GREG</FIRST_NAME>
<LAST_NAME>WINTER</LAST_NAME>
<PHONES>
<PHONE type="Office">5676733</PHONE>
<PHONE type="Office">9123434231</PHONE>
</PHONES>
<AC_NO>12313-123144_4354</AC_NO>
<AMOUNT>2800.00</AMOUNT>
</EMP>
</BODY>
</EMPDATA>
c) Load the XML files to table using SQL Loader
Execute the below command in the command prompt.
sqlldr xmlstage@devl control=load_xml.ctl
Once the command is executed successfully the XML files would have been loaded to the table. You can query the table to see the data loaded
SQL> select xmldata,file_id,file_name from xml_files;
But the output will not show the XML file content entirely.
3. Querying the data in the XMLTYPE column
a) Below query will extract emp_num, acct_num and amount from the XML
SELECT EXTRACTVALUE (VALUE (ctba), '/EMP/EMPNUM') emp_num,
EXTRACTVALUE (VALUE (ctba), '/EMP/AC_NO') acct_num,
EXTRACTVALUE (VALUE (ctba), '/EMP/AMOUNT') amount
FROM xmlstage.xml_files,
TABLE (XMLSEQUENCE (EXTRACT (xmldata, '/EMPDATA/BODY/EMP'))) ctba
b) Below Query will extract phone number and phone type. So it is little different as we have to extract the attribute of a node. We have to specify attribute with "@"
SELECT EXTRACTVALUE (VALUE (ctba), '/EMP/EMPNUM') emp_num,
TO_TIMESTAMP (EXTRACTVALUE (VALUE (ctba), '/EMP/HIRE_DATE'),
'YYYY-MM-DD HH24:MI:SS.FF'
) hire_date,
EXTRACTVALUE (VALUE (ctbb), '/PHONE/@type') phone_type,
EXTRACTVALUE (VALUE (ctbb), '/PHONE') phone
FROM xmlstage.xml_files,
TABLE (XMLSEQUENCE (EXTRACT (xmldata, '/EMPDATA/BODY/EMP'))) ctba,
TABLE (XMLSEQUENCE (EXTRACT (VALUE (ctba), '/EMP/PHONES/PHONE'))) ctbb
c) If your XML contains xml namespace attribute, you should ad xmlns as second parameter in the EXTRACT function and as third parameter in EXTRACTVALUE function.
You can use the queries like above to extract data from XMLTYPE column and insert into Tables for further processing.
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Tuesday, July 12, 2011
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