Oracle PL/SQL Tutorial/View/View Sturcutre — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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Версия 13:45, 26 мая 2010
Getting Information on View Definitions by using "desc"
SQL>
SQL>
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> CREATE VIEW myView AS
2 SELECT *
3 FROM employee
4 WITH READ ONLY CONSTRAINT my_view_read_only;
View created.
SQL>
SQL> desc myView;
Name Null? Type
--------------------
ID NOT NULL VARCHAR2(4)
FIRST_NAME VARCHAR2(10)
LAST_NAME VARCHAR2(10)
START_DATE DATE
END_DATE DATE
SALARY NUMBER(8,2)
CITY VARCHAR2(10)
DESCRIPTION VARCHAR2(15)
SQL>
SQL> drop view myView;
View dropped.
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL>
MAKE_REF and user view
SQL>
SQL>
SQL> create type addressType as object
2 (Street VARCHAR2(50),
3 City VARCHAR2(25),
4 State CHAR(2),
5 Zip NUMBER);
6 /
SQL> create type personType as object
2 (Name VARCHAR2(25),
3 Address addressType);
4 /
SQL>
SQL> create table emp
2 (cid NUMBER primary key,
3 Name VARCHAR2(25),
4 Street VARCHAR2(50),
5 City VARCHAR2(25),
6 State CHAR(2),
7 Zip NUMBER);
SQL>
SQL>
SQL> create or replace type empType as object
2 (cid NUMBER,
3 Name VARCHAR2(25),
4 Street VARCHAR2(50),
5 City VARCHAR2(25),
6 State CHAR(2),
7 Zip NUMBER);
8 /
SQL>
SQL> create view empView of empType
2 with object OID (cid) as
3 select cid, Name, Street, City, State, Zip
4 from emp;
SQL>
SQL> create table emp_CALL
2 (cid NUMBER,
3 Call_Number NUMBER,
4 Call_Date DATE,
5 constraint emp_CALL_PK primary key (cid, Call_Number),
6 constraint emp_CALL_FK foreign key (cid)references emp(cid));
SQL>
SQL>
SQL> create view empCallView as
2 select MAKE_REF(empView, cid) cid,
3 Call_Number,
4 Call_Date
5 from emp_CALL;
SQL>
SQL> select DEREF(CCOV.cid)
2 from empCallView CCOV
3 where Call_Date = TRUNC(SysDate);
SQL>
SQL>
SQL> drop view empCallView;
SQL> drop view empView;
SQL> drop table emp_CALL;
SQL> drop table emp;
SQL>
SQL>
SQL> drop type personType;
SQL>
SQL> drop type addressType;
SQL>
User view and object id
SQL> create type addressType as object
2 (Street VARCHAR2(50),
3 City VARCHAR2(25),
4 State CHAR(2),
5 Zip NUMBER);
6 /
SQL> create type personType as object
2 (Name VARCHAR2(25),
3 Address addressType);
4 /
SQL>
SQL> create table emp
2 (cid NUMBER primary key,
3 Name VARCHAR2(25),
4 Street VARCHAR2(50),
5 City VARCHAR2(25),
6 State CHAR(2),
7 Zip NUMBER);
SQL>
SQL>
SQL> create or replace type empType as object
2 (cid NUMBER,
3 Name VARCHAR2(25),
4 Street VARCHAR2(50),
5 City VARCHAR2(25),
6 State CHAR(2),
7 Zip NUMBER);
8 /
SQL>
SQL> create view empView of empType
2 with object OID (cid) as
3 select cid, Name, Street, City, State, Zip
4 from emp;
SQL>
SQL>
SQL> drop view empView;
SQL> drop table emp;
SQL>
SQL>
SQL>
SQL> drop type personType;
SQL>
SQL> drop type addressType;
SQL>
SQL>