Oracle PL/SQL Tutorial/XML/xmlelement

Create xml element with xmlelement function

SQL> CREATE TABLE products(
  2    product_id              NUMBER(6),
  3    name            VARCHAR2(50),
  4    category        VARCHAR2(50),
  5    price      NUMBER(8,2),
  6    min_price       NUMBER(8,2)
  7  );
Table created.
SQL>
SQL> select xmlelement( "Product",xmlattributes(p.product_id,p.name as "Name"),xmlforest(p.category as "Category",p.price as "price"))
  2  from products p;
no rows selected
SQL>
SQL> drop table products;
Table dropped.
SQL>
SQL>

Use XMLELEMENT to convert column data to xml format

Generating XML from "Ordinary" Tables

Oracle provides a function, XMLElement, that transforms data into XML format.

The function takes two arguments ?a the tag name and the data. Consider this example:

SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    First_Name         VARCHAR2(10 BYTE),
  4    Last_Name          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2               values ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                values("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                values("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York",  "Tester")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                values("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York",  "Manager")
  3  /
1 row created.
SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                values("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
  3  /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
  2  /
ID   FIRST_NAME           LAST_NAME            START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- -------------------- -------------------- --------- --------- ---------- ---------- ---------------
01   Jason                Martin               25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer
02   Alison               Mathews              21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester
03   James                Smith                12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia                Rice                 24-OCT-82 21-APR-99    2344.78 Vancouver  Manager
05   Robert               Black                15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda                Green                30-JUL-87 04-JAN-96    4322.78 New York   Tester
07   David                Larry                31-DEC-90 12-FEB-98    7897.78 New York   Manager
08   James                Cat                  17-SEP-96 15-APR-02    1232.78 Vancouver  Tester
8 rows selected.
SQL>
SQL>
SQL> SELECT xmlelement("Name",first_name), xmlelement("ID",id),
  2    xmlelement("City", city)
  3  FROM employee;
XMLELEMENT("NAME",FIRST_NAME)        XMLELEMENT("ID",ID)             XMLELEMENT("CITY",CITY)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
<Name>Jason</Name>                   <ID>01</ID>                     <City>Toronto</City>
<Name>Alison</Name>                  <ID>02</ID>                     <City>Vancouver</City>
<Name>James</Name>                   <ID>03</ID>                     <City>Vancouver</City>
<Name>Celia</Name>                   <ID>04</ID>                     <City>Vancouver</City>
<Name>Robert</Name>                  <ID>05</ID>                     <City>Vancouver</City>
<Name>Linda</Name>                   <ID>06</ID>                     <City>New York</City>
<Name>David</Name>                   <ID>07</ID>                     <City>New York</City>
<Name>James</Name>                   <ID>08</ID>                     <City>Vancouver</City>

8 rows selected.
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.
SQL>
SQL>

XMLElement

SQL>
SQL> SELECT XMLElement("text",XMLAttributes(2 AS "x",2 AS "y"),2) FROM dual;
XMLELEMENT("TEXT",XMLATTRIBUTES(2AS"X",2AS"Y"),2)
--------------------------------------------------------------------------------
<text x="2" y="2">2</text>