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Oracle对象类型详解

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一、抽象数据类型

1、创建类型

–地址类型

CREATE OR REPLACE TYPE AddressType AS OBJECT

(

 Country varchar2(15),

 City varchar2(20),

 Street varchar2(30)

);

 

2、类型嵌套

–创建基于前一个类型的新的抽象数据类型:巨星类型

CREATE OR REPLACE TYPE SuperStarType AS OBJECT

(

 StarName varchar2(30),

 Address AddressType

);

 

3、基于抽象类型创建关系表

CREATE TABLE SuperStar

(

 StarID varchar(10),

 Star SuperStarType

);

 

4、基于抽象类型创建对象表

CREATE TABLE SuperStarObj of SuperStarType;

 

5、使用构造方法在表中插入记录

INSERT INTO SuperStar VALUES('001',SuperStarType('Zidane',AddressType('France','Paris','People Street NO.1')));

 

6、查询表中记录

(1)SQL> SELECT * FROM SuperStar;

 

STARID

———-

STAR(STARNAME, ADDRESS(COUNTRY, CITY, STREET))

——————————————————————————–

001

SUPERSTARTYPE('Zidane', ADDRESSTYPE('France', 'Paris', 'People Street NO.1'))

 

(2)

SELECT s.StarID,s.Star.StarName,s.Star.Address.Country,s.Star.Address.City,s.Star.Address.Street FROM SuperStar s

 

STARID     STAR.STARNAME                  STAR.ADDRESS.CO STAR.ADDRESS.CITY    STAR.ADDRESS.STREET

———- —————————— ————— ——————– ———————

001    Zidane       France          Paris                People Street NO.1

 

7、抽象数据类型的继承

(1)创建一个类型

 CREATE OR REPLACE TYPE PersonType AS OBJECT

(

 PersonName varchar(10),

 PersonSex varchar(2),

 PersonBirth date

) not final;

(2)派生一个类型

CREATE OR REPLACE TYPE StudentType UNDER PersonType

(

 StudentNO int,

 StudentScore int

);

(3)查看数据字典

SQL> DESC StudentType

 StudentType extends SYS.PERSONTYPE

 Name                                                                          

 ——————————————————————————

 PERSONNAME                                                                     

 PERSONSEX                                                                     

 PERSONBIRTH                                                                   

 STUDENTNO                                                                     

 STUDENTSCORE

(4)创建对象表

CREATE TABLE student OF StudentType;

(5)向对象表中插入数据

INSERT INTO student VALUES('Rose','nv',to_date('1983-05-02','yyyy-mm-dd'),1001,98);

(6) 查询数据

SQL> SELECT * FROM student;

 

PERSONNAME PE PERSONBIR STUDENTNO STUDENTSCORE

———- — ——— ———- ————

Rose       nv 02-MAY-83          1001           98      

 

二、可变数组

1、创建带有可变数组的表

(1)创建可变数组的基类型

CREATE OR REPLACE TYPE MingXiType AS OBJECT

(

 GoodID varchar2(20),

 InCount int,

 ProviderID varchar(20)

);

(2)创建嵌套项类型的可变数组

CREATE OR REPLACE TYPE arrMingXiType AS VARRAY(100) OF MingXiType;

(3)创建一个主表

CREATE TABLE InStockOrder

 (

   OrderID varchar(15) Not Null Primary Key,

   InDate date,

   OperatorID varchar(15),

   MingXi arrMingXiType

);

 

2、操作可变数组

(1)插入数据

INSERT INTO InStockOrder

VALUES('200710110001',TO_DATE('2007-10-11','YYYY-MM-DD'),'007',

arrMingXiType(MingXiType('G001',100,'1001'),

              MingXiType('G002',888,'1002'))

);

(2)查询数据

SQL> SELECT * FROM InStockOrder;

 

ORDERID         INDATE    OPERATORID

————— ——— —————

MINGXI(GOODID, INCOUNT, PROVIDERID)

———————————————————————-

200710110001    11-OCT-07 007

ARRMINGXITYPE(MINGXITYPE('G001', 100, '1001'), MINGXITYPE('G002', 888, '1002')

(3)使用Table()函数

SQL> SELECT * FROM Table(SELECT t.MingXi FROM InStockOrder t

                 WHERE t.OrderID='200710110001');

 

GOODID                  INCOUNT PROVIDERID

——————– ———- ——————–

G001                        100 1001

G002                       888 1002

(4)修改数据

UPDATE InStockOrder

SET MingXi=arrMingXiType(MingXiType('G001',200,'1001'),

                         MingXiType('G002',8888,'1002'))

               WHERE OrderID='200710110001'

注意:不能更新VARRAY中的单个元素,必须更新整个VARRAY

 

三、嵌套表

1、创建嵌套表

(1)创建嵌套表的基类型

CREATE OR REPLACE TYPE MingXiType AS OBJECT

(

 GoodID varchar2(20),

 InCount int,

 ProviderID varchar(20)

) not final;

(2)创建嵌套表类型

CREATE OR REPLACE TYPE nestMingXiType AS TABLE OF MingXiType;

(3)创建主表,其中一列是嵌套表类型

CREATE TABLE InStockTable

 (

   OrderID varchar(15) Not Null Primary Key,

   InDate date,

   OperatorID varchar(15),

   MingXi nestMingXiType

 ) Nested Table MingXi STORE AS MingXiTable;

 

2、操作嵌套表

(1)向嵌套表中插入记录

INSERT INTO InStockTable

VALUES('20071012001',TO_DATE('2007-10-12','YYYY-MM-DD'),'007',

     nestMingXiType(MingXiType('G003',666,'1001'),

                    MingXiType('G004',888,'1002'),

                    MingXiType('G005',8888,'1003'))

);

(2)查询数据

SQL> SELECT * FROM InStockTable;

 

ORDERID         INDATE    OPERATORID

————— ——— —————

MINGXI(GOODID, INCOUNT, PROVIDERID)

—————————————————————————————————-

20071012001     12-OCT-07 007

NESTMINGXITYPE(MINGXITYPE('G003', 666, '1001'), MINGXITYPE('G004', 888, '1002'), MINGXITYPE('G005', 8888, '1003')

(3)使用Table()函数

 SQL> SELECT * FROM Table(SELECT T.MingXi FROM InStockTable t

            WHERE OrderID='20071012001')

 

GOODID                  INCOUNT PROVIDERID

——————– ———- ——————–

G003                        666 1001

G004                        888 1002

G005                       8888 1003

(4)更新嵌套表中的数据

UPDATE Table(SELECT t.MingXi FROM InStockTable t WHERE OrderID='20071012001') tt

SET tt.InCount=1666 WHERE tt.GoodID='G003';

(5)删除表中数据

DELETE Table(SELECT t.MingXi FROM InStockTable t WHERE OrderID='20071012001') tt

 WHERE tt.GoodID='G003'

 

四、对象表

1、创建对象表

CREATE TABLE ObjectTable OF MingXiType;

2、向表中插入数据

INSERT INTO ObjectTable VALUES('G001',500,'P005');

 

INSERT INTO ObjectTable VALUES('G002',1000,'P008');

3、查询对象表中的记录

A 直接查询

SQL> SELECT * FROM ObjectTable;

 

GOODID                  INCOUNT PROVIDERID

——————– ———- —————

G001                        500 P005

G002                       1000 P008

B 用VALUE()函数查询

SQL> SELECT VALUE(O) FROM ObjectTable O;

 

VALUE(O)(GOODID, INCOUNT, PROVIDERID)

——————————————

MINGXITYPE('G001', 500, 'P005')

MINGXITYPE('G002', 1000, 'P008')

4、查看对象标志符(OID)

A REF操作符引用行对象

SQL> SELECT REF(t) FROM ObjectTable t;

 

REF(T)

——————————————————————————–

0000280209771F103ED34842478A9C439CDAEFEF6324B0ACF849F14BD7A8B52F4B0297D1C90040A9

5A0000

 

0000280209A2D3359E0F0C44B3AF652B944F8823F524B0ACF849F14BD7A8B52F4B0297D1C90040A9

5A0001

B 将OID用于创建外键

CREATE TABLE Customer

( CustomerID varchar(10) PRIMARY KEY,

 CustomerName varchar(20),

 CustomerGoods REF MingXiType SCOPE IS ObjectTable,–引用MingXiType外键,关联的是OID的值

 CustomerAddress varchar(20)

);

C 向Customer表中插入数据,此表将从上面创建的对象表中引用数据

INSERT INTO Customer SELECT '007','Yuanhy',REF(O),'France'

FROM ObjectTable O

WHERE GoodID='G001';

D 查询Customer表

SQL> SELECT * FROM Customer;

 

CUSTOMERID CUSTOMERNAME

———- ——————–

CUSTOMERGOODS

—————————————————————————–

CUSTOMERADDRESS

——————–

007        Yuanhy

0000220208771F103ED34842478A9C439CDAEFEF6324B0ACF849F14BD7A8B52F4B0297D1C9

France

E 用DEREF操作符返回对象的值

SQL> SELECT CustomerID,CustomerName,DEREF(t.CustomerGoods),CustomerAddress

 2 FROM Customer t;

 

CUSTOMERID CUSTOMERNAME

———- ——————–

DEREF(T.CUSTOMERGOODS)(GOODID, INCOUNT, PROVIDERID)

—————————————————————————-

CUSTOMERADDRESS

——————–

007        Yuanhy

MINGXITYPE('G001', 500, 'P005')

France

 

五、对象视图

将关系表化装成对象表

1、 创建对象视图

A 创建基于关系表父表的对象类型

CREATE OR REPLACE TYPE depttype AS OBJECT

 (

   deptid number(10),

   deptname varchar(30),

   loc number(10)

 );

B 创建基于关系表的对象视图

CREATE VIEW deptview OF depttype WITH OBJECT OID(deptid) AS

SELECT department_id,department_name,location_id FROM dept;

C 查询视图

SQL> SELECT * FROM deptview;

 

    DEPTID DEPTNAME                              LOC

———- —————————— ———-

        10 Administration                       1700

        20 Marketing                            1800

        30 Purchasing                           1700

        40 Human Resources                      2400

        50 Shipping                             1500

        60 IT                                   1400

        70 Public Relations                     2700

 

SQL> select ref(t) from deptview t;

 

REF(T)

—————————————————————————————————-

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

2、创建引用视图(类似于关系表创建一个从表)

CREATE VIEW empview AS SELECT MAKE_REF(deptview,department_id) deptOID,employee_id,

first_name,last_name FROM emp;

 

查询对象视图empview

SQL> SELECT * FROM empview;

 

DEPTOID

—————————————————————————————————-

EMPLOYEE_ID FIRST_NAME           LAST_NAME

———– ——————– ————————-

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

        100 Steven               King

 

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

        101 Neena                Kochhar

 

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

        102 Lex                  De Haan

 

00004A038A004667BAC3685B444520A60ED30027E8F25F0000001426010001000100290000000000090604002A00078401FE

        103 Alexander            Hunold

 

Oracle对象类型也有属性方法
  创建对象类型与创建表很相似,只是实际上不为存储的数据分配空间:

  不带方法的简单对象类型:

CREATE TYPE type_name as OBJECT (
 column_1 type1,
 column_2 type2,
 …
);

  注意:AS OBJECT

  创建好对象类型之后,就可以在创建表的时候,使用该类型了,如:

CREATE TYPE HUMAN AS OBJECT(
    NAME VARCHAR2(20),
    SEX VARCHAR2(1),– F : FEMALE M:MALE
    BIRTHDAY DATE,
    NOTE VARCHAR2(300)
)

  稍后,可以用下面的语句查看:

SELECT * FROM USER_OBJECTS WHERE OBJECT_TYPE = 'TYPE'

CREATE TABLE STUDENTS(
    GUID NUMBER NOT NULL,
    STUDENTS HUMAN
)

  此下省去两个Trigger.
  插入数据的时候,可以如下:

INSERT INTO STUDENTS (STUDENT) VALUES (HUMAN('xling','M',TO_DATE('20060101','YYYYMMDD'),'测试'))

  注意:HUMAN('xling','M',TO_DATE('20060101','YYYYMMDD'),'测试'),这是个默认的构造函数.
  如果想选出性别为女(F)的记录,可以如下:

SELECT * FROM STUDENTS S WHERE S.STUDENT.SEX = 'F'

  注意:不能写成:SELECT * FROM STUDENTS WHERE STUDENT.SEX = 'F'  这样会报如下错误:ORA-00904: "STUDENT"."SEX": 标识符无效

  对象类型表:每条记录都是对象的表,称为对象类型表.它有两个使用方法:1,用作只有一个对象类型字段的表.2,用作具有对象类型字段的标准关系表.
  语法如下:

CREATE TABLE table_name OF object_type;

  例如:

CREATE TABLE TMP_STUDENTS OF HUMAN;

  用DESC TMP_STUDENTS,可以看到它的字段结构和HUMAN的结构一样.
  对象类型表有两个优点:1,从某种程度上简化了对象的使用,因为对象表的字段类型与对象类型是一致的,所以,不需要用对象名来修饰对象属性,可以把数据插入对象类型表,就像插入普通的关系表中一样:

INSERT INTO TMP_STUDENTS VALUES ('xling','M',TO_DATE('20060601','YYYYMMDD'),'对象类型表');
  当然也可用如下方法插入:
INSERT INTO TMP_STUDENTS VALUES (HUMAN('snow','F',TO_DATE('20060102','YYYYMMDD'),'用类型的构造函数'));

  第二个特点是:对象表是使用对象类型作为模板来创建表的一种便捷方式,它可以确保多个表具有相同的结构.

  对象类型表在:USER_TABLES表里是查不到的,而在USER_OBJECTS表里可以查到,而且OBJECT_TYPE = 'TABLE'

  类型在定义的时候,会自动包含一个方法,即默认的构造器.构造器的名称与对象的名称相同,它带有变量与对象类型的每个属性相对应.

  对象类型的方法:

CREATE TYPE type_name AS OBJECT (
 column1 column_type1,
 column2 column_type2,
 … ,
 MEMBER FUNCTION method_name(args_list) RETURN return_type,
 …
)

  注意:是MEMBER FUNCTION,(当然,也可是MEMBER PROCEDURE,没有返回值)

  和包(PACKAGE)一样,如果对象类型有方法的话,还要声明一个BODY:

CREATE TYPE BODY type_name AS
 
 MEMBER FUNCTION method_name RETURN return_type {AS | IS}
  variable declareations..
 BEGIN
  CODE..
  RETURN return_value;
 END;//END MEMBER FUNCTION
 …
END;//END TYPE BODY

  如下所示:

CREATE TYPE HUMAN AS OBJECT(
    NAME VARCHAR2(20),
    SEX VARCHAR2(1),– F : FEMALE M:MALE
    BIRTHDAY DATE,
    NOTE VARCHAR2(300),
   
    MEMBER FUNCTION GET_AGE RETURN NUMBER
)

–BODY
CREATE TYPE BODY HUMAN AS
    MEMBER FUNCTION GET_AGE RETURN NUMBER AS
        V_MONTHS NUMBER;
    BEGIN
      SELECT FLOOR(MONTHS_BETWEEN(SYSDATE,BIRTHDAY)/12) INTO V_MONTHS FROM DUAL;
   RETURN V_MONTHS;
    END;
END;

  
  注意:BODY的格式,不是AS OBJECT,也不是用小括号括起来的.MEMBER FUNCTION 后的AS或IS不能省略.
  还以STUDENTS表为例(注:如果类型以被某个表使用,是不能修改的,必须把相关的表删除,然后把类型删除,在一个一个新建,这里就省略了,参见前文所述)

SELECT S.STUDENT.GET_AGE() FROM STUDENTS S

  
  在提起注意:表名一定要有别名.GET_AGE()的括号不能省略,否则会提示错误.

  下面演示在一个匿名过程中的使用情况:

SET SERVEROUTPUT ON
DECLARE
    AA HUMAN;
    AGE NUMBER;
BEGIN
  AA := HUMAN('xingFairy','M',TO_DATE('19830714','YYYYMMDD'),'过程');
  AGE := AA.GET_AGE();
  DBMS_OUTPUT.PUT_LINE(AGE);
END;

  映射方法:
  映射方法是一种不带参数,并返回标准的标量Oracle SQL数据类型的方法,如NUMBER,VARCHAR2,Oracle将间接地使用这些方法执行比较运算.
  映射方法最重要的一个特点是:当在WHERE或ORDER BY等比较关系子句中使用对象时,会间接地使用映射方法.
  映射方法的声明只过是在普通方法声明的前面加一个 MAP而以,注意:映射方法是一种不带参数的方法.
MAP MEMBER FUNCTION function_name RETURN return_type

  修改前文提到的HUMAN类型:
–映射方法 MAP 

 CREATE TYPE HUMAN AS OBJECT(
    NAME VARCHAR2(20),
    SEX VARCHAR2(1),– F : FEMALE M:MALE
    BIRTHDAY DATE,–注册日期 
    REGISTERDAY DATE,
    NOTE VARCHAR2(300),
   
    MEMBER FUNCTION GET_AGE RETURN NUMBER,
    MAP MEMBER FUNCTION GET_GRADE RETURN NUMBER
)

CREATE TYPE BODY HUMAN AS
    ———————–
    MEMBER FUNCTION GET_AGE RETURN NUMBER AS
        V_MONTHS NUMBER;
    BEGIN
      SELECT FLOOR(MONTHS_BETWEEN(SYSDATE,BIRTHDAY)/12) INTO V_MONTHS FROM DUAL;
   RETURN V_MONTHS;
    END;
    ————————
    MAP MEMBER FUNCTION GET_GRADE RETURN NUMBER AS
    BEGIN
      RETURN MONTHS_BETWEEN(SYSDATE,BIRTHDAY);
    END;    
END;

  插入数据:

INSERT
INTO STUDENTS (STUDENT) VALUES
(HUMAN('xling','M',TO_DATE('19830714','YYYYMMDD'),TO_DATE('20020915','YYYYMMDD'),'
测试MAP方法'));
INSERT INTO STUDENTS (STUDENT) VALUES
(HUMAN('fairy','M',TO_DATE('19830714','YYYYMMDD'),TO_DATE('20010915','YYYYMMDD'),'
测试MAP方法'));
INSERT INTO STUDENTS (STUDENT) VALUES
(HUMAN('snow','M',TO_DATE('19830714','YYYYMMDD'),TO_DATE('20020915','YYYYMMDD'),'
测试MAP方法'));

  在执行上面的操作后,用下面这个SELECT语句可以看出映射方法的效果:
SELECT S.STUDENT.NAME,S.STUDENT.GET_GRADE() FROM STUDENTS S ORDER BY STUDENT
  它是按MAP方法GET_GRADE()的值进行排序的.注意是ORDER BY STUDENT,在提起一次需要注意,一定要用表的别名,方法后的括号不能省略,即使没有参数.
  如果想以MAP方法的结果为条件,可以如下:

SELECT S.STUDENT.NAME,S.STUDENT.GET_GRADE() FROM STUDENTS S WHERE S.STUDENT.GET_GRADE() > 50
SELECT
S.STUDENT.NAME,S.STUDENT.GET_GRADE() FROM STUDENTS S WHERE STUDENT >
HUMAN(NULL,NULL,NULL,TO_DATE('20020101','YYYYMMDD'),NULL);

  排序方法:
  先说一下SELF,Oracle里对象的SELF和JAVA里的this是同一个意思.
  对象的排序方法具有一个与对象类型相同的参数,暂称为ARG1,用于和SELF对象进行比较.如果调用方法的SELF对象比ARG1小,返回负值,如果相等,返回0,如果SELF大于ARG1,则返回值大于0.

–映射方法 MAP 

 CREATE TYPE HUMAN AS OBJECT(
    NAME VARCHAR2(20),
    SEX VARCHAR2(1),– F : FEMALE M:MALE
    BIRTHDAY DATE,
    REGISTERDAY DATE,
    NOTE VARCHAR2(300),
   
    MEMBER FUNCTION GET_AGE RETURN NUMBER,
    ORDER MEMBER FUNCTION MATCH(I_STUDENT IN HUMAN) RETURN NUMBER
)

CREATE TYPE BODY HUMAN AS
    ———————–
    MEMBER FUNCTION GET_AGE RETURN NUMBER AS
        V_MONTHS NUMBER;
    BEGIN
      SELECT FLOOR(MONTHS_BETWEEN(SYSDATE,BIRTHDAY)/12) INTO V_MONTHS FROM DUAL;
   RETURN V_MONTHS;
    END;
    ————————
    ORDER MEMBER FUNCTION MATCH(I_STUDENT IN HUMAN) RETURN NUMBER AS
    BEGIN
      RETURN REGISTERDAY – I_STUDENT.REGISTERDAY;
    END;    
END;

  注意:在声明的时候,ORDER方法的参数类型要和SELF的类型一致.

SET SERVEROUTPUT ON
DECLARE
    S1 HUMAN;
    S2 HUMAN;
BEGIN
 
  S1 := HUMAN('xling',NULL,NULL,TO_DATE('20020915','YYYYMMDD'),NULL);
  S2 := HUMAN('snow',NULL,NULL,TO_DATE('20010915','YYYYMMDD'),NULL);
 
  IF S1 > S2 THEN
    DBMS_OUTPUT.PUT_LINE(S1.NAME);
  ELSIF S1 < S2 THEN
    DBMS_OUTPUT.PUT_LINE(S2.NAME);
  ELSE
    DBMS_OUTPUT.PUT_LINE('EQUAL');
  END IF;
END; 

  注意S1 和 S2是怎么比较的.

  映射方法具有效率方面的优势,因为它把每个对象与单个标量值联系在一起;排序方法有灵活方面的优势,它可以在两个对象之间进行任意复杂的比较.排序方法比映射方法的速度慢.

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