Oracle PL/SQL Tutorial/XML/Introduction — различия между версиями
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Текущая версия на 10:06, 26 мая 2010
Содержание
- 1 Create a table to hold the simple "Hello World" XML document
- 2 Create table based on single data type
- 3 Create table myTable of xmltype
- 4 SQL to XML
- 5 Use Aggregrate functions on XML data
- 6 Use Text() function to get text value from xml string
- 7 Without the text() operator, returns node name + text value
- 8 xmlagg and xmlforest
Create a table to hold the simple "Hello World" XML document
SQL> CREATE TABLE myTable
2 (id NUMBER PRIMARY KEY
3 ,doc XMLType NOT NULL)
4 XMLTYPE doc STORE AS CLOB
5 /
Table created.
SQL>
SQL>
SQL>
SQL> DECLARE
2 v_doc XMLType;
3 v_text varchar2(100);
4 BEGIN
5 select doc into v_doc from myTable
6 where id = 2;
7
8 v_text := v_doc.extract("/message/body/text()" ).getstringval;
9
10 dbms_output.put_line(v_text);
11 END;
12 /
SQL>
SQL> drop table myTable;
Table dropped.
SQL>
Create table based on single data type
SQL> create table myTable of xmltype;
Table created.
SQL>
SQL> insert into myTable values(XMLTYPE("
2 <customer>
3 <name>name value</name>
4 <telephone>123 555-1234</telephone>
5 </customer>"))
6 /
1 row created.
SQL>
SQL> select * from myTable;
SYS_NC_ROWINFO$
------------------------------------------------------
<customer>
<name>name value</name>
<telephone>123 555-1234</telephone>
1 row selected.
SQL>
SQL>
SQL> drop table myTable;
Table dropped.
Create table myTable of xmltype
SQL> create table myTable of xmltype;
Table created.
SQL>
SQL> insert into myTable values(XMLTYPE("
2 <customer>
3 <name>name value</name>
4 <telephone>123 555-1234</telephone>
5 </customer>"))
6 /
1 row created.
SQL>
SQL> select * from myTable;
SYS_NC_ROWINFO$
------------------------------------------------------
<customer>
<name>name value</name>
<telephone>123 555-1234</telephone>
1 row selected.
SQL>
SQL>
SQL> drop table myTable;
Table dropped.
SQL to XML
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>
Use Aggregrate functions on XML data
SQL> CREATE TABLE myTable
2 (myID NUMBER PRIMARY KEY,
3 myValue XMLTYPE )
4 XMLTYPE myValue STORE AS CLOB
5 /
Table created.
SQL>
SQL>
SQL> select count(extract(myValue,"/ROWSET") )
2 AS count
3 from myTable;
COUNT
----------
0
1 row selected.
SQL>
SQL>
SQL> drop table myTable;
Table dropped.
SQL>
Use Text() function to get text value from xml string
SQL> CREATE TABLE myTable(
2 id NUMBER PRIMARY KEY,
3 emps XMLType NOT NULL
4 );
Table created.
SQL>
SQL> INSERT INTO myTable VALUES (1, xmltype("<?xml version="1.0" standalone="no"
?>
2 <emps>
3 <emp>
4 <home_address>address 1</home_address>
5 </emp>
6 </emps>")
7 );
1 row created.
SQL>
SQL>
SQL> select extract(emps, "/emps/emp/home_address/text()" )
2 from myTable
3 /
EXTRACT(EMPS,"/EMPS/EMP/HOME_ADDRESS/TEXT()")
------------------------------------------------------
address 1
1 row selected.
SQL>
SQL>
SQL> drop table myTable;
Table dropped.
SQL>
SQL>
SQL>
Without the text() operator, returns node name + text value
SQL> CREATE TABLE myTable(
2 id NUMBER PRIMARY KEY
3 ,doc XMLType NOT NULL
4 )
5 XMLTYPE doc STORE AS CLOB
6 /
Table created.
SQL>
SQL>
SQL> select extract(doc, "/message/greeting")
2 from myTable;
no rows selected
SQL>
SQL>
SQL> drop table myTable;
Table dropped.
xmlagg and xmlforest
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> select xmlelement( "Prodcategory",
2 xmlattributes(p.category as "Category"),
3 xmlagg(xmlelement("Product",
4 xmlforest(p.name as "Name"))))
5 from products p
6 group by p.category;
no rows selected
SQL>
SQL> drop table products;
Table dropped.