в 13:45, 26 мая 2010

2010-05-26T13:45:46Z

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2010-05-26T10:04:45Z

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== CREATE a Table that References Our Row Objects==



<source lang="sql">
SQL>
SQL> CREATE OR REPLACE TYPE addressType as OBJECT(
2 street VARCHAR2(20),
3 city VARCHAR2(20),
4 state CHAR(2),
5 zip CHAR(5))
6 /
Type created.
SQL>
SQL> CREATE TABLE address_table OF addressType
2 /
Table created.
SQL>
SQL> CREATE TABLE client (name VARCHAR2(20),
2 address REF addressType scope is address_table)
3 /
Table created.
SQL>
SQL> DESC client;
Name Null? Type
--------
NAME VARCHAR2(20)
ADDRESS REF OF ADDRESSTYPE
SQL>
SQL> drop table client;
Table dropped.
SQL>
SQL> drop table address_table;
Table dropped.
SQL> drop type addresstype;
Type dropped.
SQL>
SQL></source>

== Inserting a Row into the Object Reference table==



<source lang="sql">
SQL>
SQL>
SQL> CREATE Or Replace TYPE AddressType AS OBJECT (
2 street VARCHAR2(15),
3 city VARCHAR2(15),
4 state CHAR(2),
5 zip VARCHAR2(5)
6 )
7 /
Type created.
SQL>
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
2 id NUMBER,
3 first_name VARCHAR2(10),
4 last_name VARCHAR2(10),
5 dob DATE,
6 phone VARCHAR2(12),
7 address AddressType
8 )
9 /
Type created.
SQL>
SQL> CREATE TABLE object_customers OF PersonType
2 /
Table created.
SQL>
SQL> INSERT INTO object_customers VALUES (
2 PersonType(1, "John", "White", "04-FEB-1945", "800-555-5555",
3 AddressType("2 Ave", "City", "MA", "12345")
4 )
5 );
1 row created.
SQL>
SQL> INSERT INTO object_customers (
2 id, first_name, last_name, dob, phone,
3 address
4 ) VALUES (
5 2, "James", "Green", "05-FEB-1968", "800-555-4444",
6 AddressType("3 Ave", "Town", "CA", "12345")
7 );
1 row created.
SQL>
SQL> CREATE Or Replace TYPE ProductType AS OBJECT (
2 id NUMBER,
3 name VARCHAR2(15),
4 description VARCHAR2(22),
5 price NUMBER(5, 2),
6 days_valid NUMBER
7 )
8 /
Type created.
SQL>
SQL> CREATE TABLE object_products OF ProductType
2 /
Table created.
SQL>
SQL> INSERT INTO object_products (
2 id, name, description, price, days_valid
3 ) VALUES (
4 1, "AAA", "BBB", 2.99, 5
5 );
1 row created.
SQL>
SQL> CREATE TABLE purchases (
2 id NUMBER PRIMARY KEY,
3 customer REF PersonType SCOPE IS object_customers,
4 product REF ProductType SCOPE IS object_products
5 );
Table created.
SQL>
SQL> INSERT INTO purchases (
2 id,
3 customer,
4 product
5 ) VALUES (
6 1,
7 (SELECT REF(oc) FROM object_customers oc WHERE oc.id = 1),
8 (SELECT REF(op) FROM object_products op WHERE op.id = 1)
9 );
1 row created.
SQL>
SQL> select * from purchases;
ID CUSTOMER PRODUCT
-----------------------------------------------------------------------------------------------
1 0000220208F78428F66B3B4357A7E2EE26FB982C67E070E7307E2E4FE6A60A03B82FDF9C49 0000220208473CFDED543D404C920B9AB1E2A37337F5BD01A93C83419084C662D11524FB08

SQL>
SQL> drop table purchases;
Table dropped.
SQL>
SQL> drop table object_products;
Table dropped.
SQL>
SQL> drop table object_customers;
Table dropped.
SQL>
SQL> drop type persontype;
Type dropped.
SQL> drop type addresstype;
Type dropped.
SQL></source>

== Object References and Object Identifiers==

<OL><LI>You use object references to model relationships between object tables, rather than foreign keys.</LI><LI>Object references are defined using the REF type.</LI><LI>Object references are basically pointers to objects in an object table.</LI><LI>Each object in an object table has a unique object identifier (OID) that you can then store in a REF column.</LI><LI>The SCOPE IS clause restricts the object reference to point to objects in a specific table.</LI><LI>The following example creates a table named purchases that contains two REF columns:</LI></OL>



<source lang="sql">
SQL>
SQL>
SQL> CREATE Or Replace TYPE ProductType AS OBJECT (
2 id NUMBER,
3 name VARCHAR2(15),
4 description VARCHAR2(22),
5 price NUMBER(5, 2),
6 days_valid NUMBER,
7
8 MEMBER FUNCTION getByDate RETURN DATE
9 );
10 /
SQL> CREATE Or Replace TYPE AddressType AS OBJECT (
2 street VARCHAR2(15),
3 city VARCHAR2(15),
4 state CHAR(2),
5 zip VARCHAR2(5)
6 );
7 /
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
2 id NUMBER,
3 first_name VARCHAR2(10),
4 last_name VARCHAR2(10),
5 dob DATE,
6 phone VARCHAR2(12),
7 address AddressType
8 );
9 /
SQL> CREATE TABLE object_employee OF PersonType;
Table created.
SQL>
SQL>
SQL> CREATE TABLE object_products OF ProductType;
Table created.
SQL>
SQL> CREATE TABLE purchases (
2 id NUMBER PRIMARY KEY,
3 customer REF PersonType SCOPE IS object_employee,
4 product REF ProductType SCOPE IS object_products
5 );
Table created.
SQL>
SQL> drop table purchases;
Table dropped.
SQL>
SQL> drop table object_employee;
Table dropped.
SQL>
SQL> drop table object_products;
Table dropped.</source>

== Reference column==



<source lang="sql">
SQL> CREATE OR REPLACE TYPE addressType as OBJECT(
2 street VARCHAR2(20),
3 city VARCHAR2(20),
4 state CHAR(2),
5 zip CHAR(5))
6 /
Type created.
SQL>
SQL> CREATE TABLE address_table OF addressType
2 /
Table created.
SQL>
SQL> CREATE TABLE client (name VARCHAR2(20),
2 address REF addressType scope is address_table)
3 /
Table created.
SQL>
SQL>
SQL> DESC client;
Name Null? Type
---------
NAME VARCHAR2(20)
ADDRESS REF OF ADDRESSTYPE
SQL>
SQL> INSERT INTO client VALUES ("Jones",null);
1 row created.
SQL>
SQL> SELECT *
2 FROM client;
NAME ADDRESS
-------------------- --------------------------------------------------
Jones
SQL>
SQL>
SQL> UPDATE client SET address =
2 (SELECT REF(aa)
3 FROM address_table aa
4 WHERE aa.city LIKE "Mob%")
5 WHERE name = "Jones"
6
SQL> select * from client;
NAME ADDRESS
-------------------- --------------------------------------------------
Jones
SQL>
SQL> DEREF (Dereference) the Row Addresses
SQL> SELECT name, DEREF(address)
2 FROM client;
NAME
--------------------
DEREF(ADDRESS)(STREET, CITY, STATE, ZIP)
-----------------------------------------
Jones

SQL>
SQL>
SQL> drop table address_table;
Table dropped.
SQL> drop table client;
Table dropped.
SQL>
SQL> drop type addresstype;
Type dropped.
SQL>
SQL></source>

== Selecting a Row from the Object reference table==



<source lang="sql">
SQL>
SQL> CREATE Or Replace TYPE AddressType AS OBJECT (
2 street VARCHAR2(15),
3 city VARCHAR2(15),
4 state CHAR(2),
5 zip VARCHAR2(5)
6 )
7 /
Type created.
SQL>
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
2 id NUMBER,
3 first_name VARCHAR2(10),
4 last_name VARCHAR2(10),
5 dob DATE,
6 phone VARCHAR2(12),
7 address AddressType
8 )
9 /
Type created.
SQL>
SQL> CREATE TABLE object_customers OF PersonType;
Table created.
SQL>
SQL> INSERT INTO object_customers VALUES (
2 PersonType(1, "John", "White", "04-FEB-1945", "800-555-5555",
3 AddressType("2 Ave", "City", "MA", "12345")
4 )
5 );
1 row created.
SQL>
SQL> INSERT INTO object_customers (
2 id, first_name, last_name, dob, phone,
3 address
4 ) VALUES (
5 2, "James", "Green", "05-FEB-1968", "800-555-4444",
6 AddressType("3 Ave", "Town", "CA", "12345")
7 );
1 row created.
SQL>
SQL> CREATE Or Replace TYPE ProductType AS OBJECT (
2 id NUMBER,
3 name VARCHAR2(15),
4 description VARCHAR2(22),
5 price NUMBER(5, 2),
6 days_valid NUMBER
7 )
8 /
Type created.
SQL>
SQL> CREATE TABLE object_products OF ProductType
2 /
Table created.
SQL>
SQL> INSERT INTO object_products (
2 id, name, description, price, days_valid
3 ) VALUES (
4 1, "AAA", "BBB", 2.99, 5
5 );
1 row created.
SQL>
SQL> CREATE TABLE purchases (
2 id NUMBER PRIMARY KEY,
3 customer REF PersonType SCOPE IS object_customers,
4 product REF ProductType SCOPE IS object_products
5 )
6 /
Table created.
SQL>
SQL> INSERT INTO purchases (
2 id,
3 customer,
4 product
5 ) VALUES (
6 1,
7 (SELECT REF(oc) FROM object_customers oc WHERE oc.id = 1),
8 (SELECT REF(op) FROM object_products op WHERE op.id = 1)
9 );
1 row created.
SQL> select * from purchases;
ID CUSTOMER PRODUCT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 00002202084DE5F9FDE0704131B2DA2477DE28C548B2AF244ECB1E42B686FFFBAD0C5A8874 0000220208A772FB501EEF4A958FA182D42AF06C9072FFE34E8F8E4FC99B4C52F83340B041

SQL>
SQL> drop table purchases;
Table dropped.
SQL>
SQL> drop table object_products;
Table dropped.
SQL>
SQL> drop table object_customers;
Table dropped.
SQL>
SQL> drop type persontype;
Type dropped.
SQL>
SQL> drop type addresstype;
Type dropped.
SQL></source>

== Updating a Row in the object reference table==



<source lang="sql">
SQL>
SQL>
SQL> CREATE Or Replace TYPE AddressType AS OBJECT (
2 street VARCHAR2(15),
3 city VARCHAR2(15),
4 state CHAR(2),
5 zip VARCHAR2(5)
6 )
7 /
Type created.
SQL>
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
2 id NUMBER,
3 first_name VARCHAR2(10),
4 last_name VARCHAR2(10),
5 dob DATE,
6 phone VARCHAR2(12),
7 address AddressType
8 )
9 /
Type created.
SQL>
SQL> CREATE TABLE object_customers OF PersonType
2 /
Table created.
SQL>
SQL> INSERT INTO object_customers VALUES (
2 PersonType(1, "John", "White", "04-FEB-1945", "800-555-5555",
3 AddressType("2 Ave", "town", "MA", "12345")
4 )
5 );
1 row created.
SQL>
SQL> INSERT INTO object_customers (
2 id, first_name, last_name, dob, phone,
3 address
4 ) VALUES (
5 2, "James", "Green", "05-FEB-1968", "800-555-4444",
6 AddressType("3 Ave", "Town", "CA", "12345")
7 );
1 row created.
SQL>
SQL> CREATE Or Replace TYPE ProductType AS OBJECT (
2 id NUMBER,
3 name VARCHAR2(15),
4 description VARCHAR2(22),
5 price NUMBER(5, 2),
6 days_valid NUMBER
7 )
8 /
Type created.
SQL>
SQL> CREATE TABLE object_products OF ProductType
2 /
Table created.
SQL>
SQL> INSERT INTO object_products (
2 id, name, description, price, days_valid
3 ) VALUES (
4 1, "AAA", "BBB", 2.99, 5
5 );
1 row created.
SQL>
SQL> CREATE TABLE purchases (
2 id NUMBER PRIMARY KEY,
3 customer REF PersonType SCOPE IS object_customers,
4 product REF ProductType SCOPE IS object_products
5 )
6 /
Table created.
SQL>
SQL> INSERT INTO purchases (
2 id,
3 customer,
4 product
5 ) VALUES (
6 1,
7 (SELECT REF(oc) FROM object_customers oc WHERE oc.id = 1),
8 (SELECT REF(op) FROM object_products op WHERE op.id = 1)
9 );
1 row created.
SQL> select * from purchases;
ID CUSTOMER PRODUCT
-----------------------------------------------------------------------------------------
1 000022020818702007EFFB4B20A2177B51CC69DC1F5F9D95B91B624DC88DB51BA9B83230D8 0000220208DC78B0F6B61E431FABCBEF463314969A9109C12B203A4E03B462604D027BE27E

SQL>
SQL> UPDATE purchases SET product = (
2 SELECT REF(op) FROM object_products op WHERE op.id = 2
3 ) WHERE id = 1;
1 row updated.
SQL>
SQL> drop table purchases;
Table dropped.
SQL>
SQL> drop table object_products;
Table dropped.
SQL>
SQL> drop table object_customers;
Table dropped.
SQL> drop type persontype;
Type dropped.
SQL> drop type addresstype;
Type dropped.
SQL></source>

== You can access the rows in the object tables that are pointed to by REF column values using t REF() function; this function accepts a REF column as a parameter.==



<source lang="sql">
SQL>
SQL> CREATE Or Replace TYPE AddressType AS OBJECT (
2 street VARCHAR2(15),
3 city VARCHAR2(15),
4 state CHAR(2),
5 zip VARCHAR2(5)
6 )
7 /
Type created.
SQL>
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
2 id NUMBER,
3 first_name VARCHAR2(10),
4 last_name VARCHAR2(10),
5 dob DATE,
6 phone VARCHAR2(12),
7 address AddressType
8 )
9 /
Type created.
SQL>
SQL> CREATE TABLE object_customers OF PersonType
2 /
Table created.
SQL>
SQL> INSERT INTO object_customers VALUES (
2 PersonType(1, "John", "White", "04-FEB-1945", "800-555-5555",
3 AddressType("2 Ave", "City", "MA", "12345")
4 )
5 );
1 row created.
SQL>
SQL> INSERT INTO object_customers (
2 id, first_name, last_name, dob, phone,
3 address
4 ) VALUES (
5 2, "James", "Green", "05-FEB-1968", "800-555-4444",
6 AddressType("3 Ave", "Town", "CA", "12345")
7 );
1 row created.
SQL>
SQL> CREATE Or Replace TYPE ProductType AS OBJECT (
2 id NUMBER,
3 name VARCHAR2(15),
4 description VARCHAR2(22),
5 price NUMBER(5, 2),
6 days_valid NUMBER
7 )
8 /
Type created.
SQL>
SQL> CREATE TABLE object_products OF ProductType
2 /
Table created.
SQL>
SQL> INSERT INTO object_products (
2 id, name, description, price, days_valid
3 ) VALUES (
4 1, "AAA", "BBB", 2.99, 5
5 );
1 row created.
SQL>
SQL> CREATE TABLE purchases (
2 id NUMBER PRIMARY KEY,
3 customer REF PersonType SCOPE IS object_customers,
4 product REF ProductType SCOPE IS object_products
5 );
Table created.
SQL>
SQL> INSERT INTO purchases (
2 id,
3 customer,
4 product
5 ) VALUES (
6 1,
7 (SELECT REF(oc) FROM object_customers oc WHERE oc.id = 1),
8 (SELECT REF(op) FROM object_products op WHERE op.id = 1)
9 );
1 row created.
SQL>
SQL> select * from purchases;
ID CUSTOMER PRODUCT
-------------------------------------------------------------------------------------------------------------------------------------------------------------
1 000022020861FDF674DA3D4B1088D187CB56924C27CD0C0B2EF27A4E5AB731BDCEE0BF1441 0000220208F8102DD78DC54DD0BB75E4AEA43E91BF05A396E7F9534DAE9CE3FE3F78872A74

SQL>
SQL> SELECT DEREF(customer), DEREF(product)
2 FROM purchases;
DEREF(CUSTOMER)(ID, FIRST_NAME, LAST_NAME, DOB, PHONE, ADDRESS(STREET, CITY, STATE, ZIP))
-------------------------------------------------------------------------------------------
DEREF(PRODUCT)(ID, NAME, DESCRIPTION, PRICE, DAYS_VALID)
------------------------------------------------------------------------------------------
PERSONTYPE(1, "John", "White", "04-FEB-45", "800-555-5555", ADDRESSTYPE("2 Ave", "City", "MA", "12345"))
PRODUCTTYPE(1, "AAA", "BBB", 2.99, 5)

SQL>
SQL> drop table purchases;
Table dropped.
SQL>
SQL> drop table object_products;
Table dropped.
SQL>
SQL> drop table object_customers;
Table dropped.
SQL>
SQL> drop type persontype;
Type dropped.
SQL> drop type addresstype;
Type dropped.
SQL></source>

== You can access this object identifier using the REF() function and store the returned objectifier in a REF column.==



<source lang="sql">
SQL>
SQL> CREATE or Replace TYPE AddressType AS OBJECT (
2 street VARCHAR2(15),
3 city VARCHAR2(15),
4 state CHAR(2),
5 zip VARCHAR2(5)
6 )
7 /
Type created.
SQL>
SQL> CREATE Or Replace TYPE PersonType AS OBJECT (
2 id NUMBER,
3 first_name VARCHAR2(10),
4 last_name VARCHAR2(10),
5 dob DATE,
6 phone VARCHAR2(12),
7 address AddressType
8 )
9 /
Type created.
SQL>
SQL> CREATE TABLE object_customers OF PersonType
2 /
Table created.
SQL>
SQL> INSERT INTO object_customers VALUES (
2 PersonType(1, "John", "White", "04-FEB-1945", "800-555-5555",
3 AddressType("2 Ave", "town", "AA", "12345")
4 )
5 );
1 row created.
SQL>
SQL> INSERT INTO object_customers (
2 id, first_name, last_name, dob, phone,
3 address
4 ) VALUES (
5 2, "James", "Green", "05-FEB-1968", "800-555-4444",
6 AddressType("3 Ave", "City", "CA", "12345")
7 );
1 row created.
SQL>
SQL> CREATE Or Replace TYPE ProductType AS OBJECT (
2 id NUMBER,
3 name VARCHAR2(15),
4 description VARCHAR2(22),
5 price NUMBER(5, 2),
6 days_valid NUMBER
7 )
8 /
Type created.
SQL>
SQL> CREATE TABLE object_products OF ProductType
2 /
Table created.
SQL>
SQL> INSERT INTO object_products (
2 id, name, description, price, days_valid
3 ) VALUES (
4 1, "AAA", "BBB", 2.99, 5
5 );
1 row created.
SQL>
SQL> CREATE TABLE purchases (
2 id NUMBER PRIMARY KEY,
3 customer REF PersonType SCOPE IS object_customers,
4 product REF ProductType SCOPE IS object_products
5 );
Table created.
SQL>
SQL> INSERT INTO purchases (
2 id,
3 customer,
4 product
5 ) VALUES (
6 1,
7 (SELECT REF(oc) FROM object_customers oc WHERE oc.id = 1),
8 (SELECT REF(op) FROM object_products op WHERE op.id = 1)
9 );
1 row created.
SQL> select * from purchases;
ID CUSTOMER PRODUCT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 00002202089E1785E0E6A5410BA917BACC9F93530B35C60A986EAC46F580144901E1EC0F94 00002202088CDC8C88E9AB403D85085FAE2649DF6E02D3BDE222D24D1E85421901D500B4A2

SQL>
SQL> drop table purchases;
Table dropped.
SQL>
SQL> drop table object_products;
Table dropped.
SQL>
SQL> drop table object_customers;
Table dropped.
SQL> drop type persontype;
Type dropped.
SQL> drop type addresstype;
Type dropped.
SQL></source>

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