Oracle PL/SQL/View/Create View
Содержание
- 1 Create a simple view
- 2 Create a view with check option
- 3 create force view
- 4 create materialized view
- 5 Create or replace a view
- 6 Create OR REPLACE VIEW from selected columns in a table
- 7 Create view by join three tables
- 8 Create view on single field of a type
- 9 Create view without indiating the column name
- 10 User view and object id
- 11 Use view based on user-defind type
- 12 Using view to simplify the query
Create a simple view
<source lang="sql">
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> SQL> SQL> SQL> SQL> create view view_employee as
2 select id view_id, first_name view_first_name 3 from employee;
View created. SQL> SQL> SQL> select * from view_employee; VIEW VIEW_FIRST
----------
01 Jason 02 Alison 03 James 04 Celia 05 Robert 06 Linda 07 David 08 James 8 rows selected. SQL> SQL> SQL> drop view view_employee; View dropped. SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL> SQL> SQL>
</source>
Create a view with check option
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE departments
2 (department_id number(10) not null, 3 department_name varchar2(50) not null, 4 CONSTRAINT departments_pk PRIMARY KEY (department_id) 5 );
Table created. SQL> SQL> SQL> SQL> insert into departments ( department_id, department_name )
2 values( 1, "Data Group" );
1 row created. SQL> SQL> insert into departments ( department_id, department_name )
2 values( 2, "Purchasing" );
1 row created. SQL> SQL> insert into departments ( department_id, department_name )
2 values( 3, "Call Center" );
1 row created. SQL> SQL> insert into departments ( department_id, department_name )
2 values( 4, "Communication" );
1 row created. SQL> SQL> SQL> SQL> CREATE TABLE employees
2 ( employee_id number(10) not null, 3 last_name varchar2(50) not null, 4 email varchar2(30), 5 hire_date date, 6 job_id varchar2(30), 7 department_id number(10), 8 salary number(6), 9 manager_id number(6), 10 CONSTRAINT employees_pk PRIMARY KEY (employee_id), 11 CONSTRAINT fk_departments FOREIGN KEY (department_id) REFERENCES departments(department_id) 12 );
Table created. SQL> SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary,department_id ,manager_id)
2 values ( 1001, "Lawson", "lawson@g.ru", "01-JAN-2002","MGR", 30000,1 ,1004);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
2 values ( 1002, "Wells", "wells@g.ru", "01-JAN-2002", "DBA", 20000,2, 1005 );
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
2 values( 1003, "Bliss", "bliss@g.ru", "01-JAN-2002", "PROG", 24000,3 ,1004);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1004, "Kyte", "tkyte@a.ru", SYSDATE-3650, "MGR",25000 ,4, 1005);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1005, "Viper", "sdillon@a .ru", SYSDATE, "PROG", 20000, 1, 1006);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id,manager_id)
2 values( 1006, "Beck", "clbeck@g.ru", SYSDATE, "PROG", 20000, 2, null);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1007, "Java", "java01@g.ru", SYSDATE, "PROG", 20000, 3, 1006);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1008, "Oracle", "wvelasq@g.ru", SYSDATE, "DBA", 20000, 4, 1006);
1 row created. SQL> SQL> SQL> SQL> create or replace view department_10 as
2 select * 3 from employees 4 where department_id = 10 5 with check option;
View created. SQL> SQL> SQL> drop table employees cascade constraints; Table dropped. SQL> drop table departments cascade constraints; Table dropped. SQL>
</source>
create force view
<source lang="sql">
SQL> SQL> SQL> create view invalid_view as
2 select * from table_that_does_not_exist; select * from table_that_does_not_exist *
ERROR at line 2: ORA-00942: table or view does not exist
SQL> SQL> create force view invalid_view as
2 select * from table_that_does_not_exist;
Warning: View created with compilation errors. SQL> SQL> drop view invalid_view; View dropped. SQL> SQL>
</source>
create materialized view
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE employees
2 ( employee_id number(10) not null, 3 last_name varchar2(50) not null, 4 email varchar2(30), 5 hire_date date, 6 job_id varchar2(30), 7 department_id number(10), 8 salary number(6), 9 manager_id number(6) 10 );
Table created. SQL> SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary,department_id ,manager_id)
2 values ( 1001, "Lawson", "lawson@g.ru", "01-JAN-2002","MGR", 30000,1 ,1004);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
2 values ( 1002, "Wells", "wells@g.ru", "01-JAN-2002", "DBA", 20000,2, 1005 );
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id ,manager_id)
2 values( 1003, "Bliss", "bliss@g.ru", "01-JAN-2002", "PROG", 24000,3 ,1004);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1004, "Kyte", "tkyte@a.ru", SYSDATE-3650, "MGR",25000 ,4, 1005);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1005, "Viper", "sdillon@a .ru", SYSDATE, "PROG", 20000, 1, 1006);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id,manager_id)
2 values( 1006, "Beck", "clbeck@g.ru", SYSDATE, "PROG", 20000, 2, null);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1007, "Java", "java01@g.ru", SYSDATE, "PROG", 20000, 3, 1006);
1 row created. SQL> SQL> insert into employees( employee_id, last_name, email, hire_date, job_id, salary, department_id, manager_id)
2 values( 1008, "Oracle", "wvelasq@g.ru", SYSDATE, "DBA", 20000, 4, 1006);
1 row created. SQL> SQL> SQL> SQL> set timing off SQL> SQL> create materialized view my_orders_mv
2 build immediate 3 refresh on commit 4 enable query rewrite 5 as 6 select employee_id, 7 count(*) total_orders 8 from employees 9 group by employee_id 10 / from employees *
ERROR at line 8: ORA-00439: feature not enabled: Materialized view rewrite
SQL> SQL> set timing on SQL> select * from my_orders_mv;
select * from my_orders_mv *
ERROR at line 1: ORA-00942: table or view does not exist
Elapsed: 00:00:00.07 SQL> set timing off SQL> drop table employees; Table dropped. SQL> SQL>
</source>
Create or replace a view
<source lang="sql">
SQL> SQL> create table t(
2 id number, 3 data varchar2(200) );
Table created. SQL> SQL> SQL> create or replace view view_t as
2 select id view_id, data view_data 3 from t;
View created. SQL> SQL> select * from view_t; no rows selected SQL> SQL> drop table t; Table dropped. SQL>
</source>
Create OR REPLACE VIEW from selected columns in a table
<source lang="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> SQL> SQL> CREATE OR REPLACE VIEW myView (First_Name, Last_Name) AS
2 select First_Name, 3 Last_Name 4 from Employee 5 where Salary > 2000;
View created. SQL> SQL> SQL> select * from myView; FIRST_NAME LAST_NAME
----------
Alison Mathews James Smith Celia Rice Robert Black Linda Green David Larry 6 rows selected. SQL> SQL> SQL> drop view myView; View dropped. SQL> SQL> SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL> SQL> SQL>
</source>
Create view by join three tables
<source lang="sql">
SQL> create table emp
2 ( empno NUMBER(4) constraint E_PK primary key 3 , ename VARCHAR2(8) 4 , init VARCHAR2(5) 5 , job VARCHAR2(8) 6 , mgr NUMBER(4) 7 , bdate DATE 8 , sal NUMBER(6,2) 9 , comm NUMBER(6,2) 10 , deptno NUMBER(2) default 10 11 ) ;
Table created. SQL> insert into emp values(1,"Tom","N", "TRAINER", 13,date "1965-12-17", 800 , NULL, 20); 1 row created. SQL> insert into emp values(2,"Jack","JAM", "Tester",6,date "1961-02-20", 1600, 300, 30); 1 row created. SQL> insert into emp values(3,"Wil","TF" , "Tester",6,date "1962-02-22", 1250, 500, 30); 1 row created. SQL> insert into emp values(4,"Jane","JM", "Designer", 9,date "1967-04-02", 2975, NULL, 20); 1 row created. SQL> insert into emp values(5,"Mary","P", "Tester",6,date "1956-09-28", 1250, 1400, 30); 1 row created. SQL> insert into emp values(6,"Black","R", "Designer", 9,date "1963-11-01", 2850, NULL, 30); 1 row created. SQL> insert into emp values(7,"Chris","AB", "Designer", 9,date "1965-06-09", 2450, NULL, 10); 1 row created. SQL> insert into emp values(8,"Smart","SCJ", "TRAINER", 4,date "1959-11-26", 3000, NULL, 20); 1 row created. SQL> insert into emp values(9,"Peter","CC", "Designer",NULL,date "1952-11-17", 5000, NULL, 10); 1 row created. SQL> insert into emp values(10,"Take","JJ", "Tester",6,date "1968-09-28", 1500, 0, 30); 1 row created. SQL> insert into emp values(11,"Ana","AA", "TRAINER", 8,date "1966-12-30", 1100, NULL, 20); 1 row created. SQL> insert into emp values(12,"Jane","R", "Manager", 6,date "1969-12-03", 800 , NULL, 30); 1 row created. SQL> insert into emp values(13,"Fake","MG", "TRAINER", 4,date "1959-02-13", 3000, NULL, 20); 1 row created. SQL> insert into emp values(14,"Mike","TJA","Manager", 7,date "1962-01-23", 1300, NULL, 10); 1 row created. SQL> SQL> create table departments
2 ( deptno NUMBER(2) constraint D_PK primary key 3 , dname VARCHAR2(10) 4 , location VARCHAR2(8) 5 , mgr NUMBER(4) 6 ) ;
Table created. SQL> SQL> insert into departments values (10,"ACCOUNTING","NEW YORK",7); 1 row created. SQL> insert into departments values (20,"TRAINING", "DALLAS", 4); 1 row created. SQL> insert into departments values (30,"SALES", "CHICAGO", 6); 1 row created. SQL> insert into departments values (40,"HR", "BOSTON", 9); 1 row created. SQL> SQL> create view empdept_v as
2 select e.empno 3 , e.ENAME 4 , e.init 5 , d.dname 6 , d.location 7 , m.ENAME as Designer 8 from emp e 9 join 10 departments d using (deptno) 11 join 12 emp m on (m.empno = d.mgr);
SQL> drop table emp; Table dropped. SQL> drop table departments; Table dropped.
</source>
Create view on single field of a type
<source lang="sql">
SQL> create type addressType as object
2 (Street VARCHAR2(50), 3 City VARCHAR2(25), 4 State CHAR(2), 5 Zip NUMBER); 6 /
SQL> SQL> create type personType as object
2 (Name VARCHAR2(25), 3 Address addressType); 4 /
SQL> SQL> SQL> create or replace type personType as object
2 (Name VARCHAR2(25), 3 Address addressType); 4 /
SQL> SQL> SQL> create table myemp
2 (cid NUMBER, 3 Person personType);
SQL> SQL> SQL> insert into myemp values(1,personType("SomeName",addressType("StreetValue","CityValue","ST",11111))); SQL> SQL> SQL> create index empview
2 on myemp(Person.Address.City);
SQL> SQL> SQL> drop table myemp; SQL> drop type personType; SQL> drop type addressType; SQL> SQL> SQL> SQL>
</source>
Create view without indiating the column name
<source lang="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> SQL> -- Create View SQL> SQL> SQL> SQL> SQL> CREATE VIEW EmployeeView AS
2 select First_Name, Last_Name from Employee;
View created. SQL> SQL> SQL> SELECT * FROM EmployeeView ORDER BY First_Name; FIRST_NAME LAST_NAME
----------
Alison Mathews Celia Rice David Larry James Smith James Cat Jason Martin Linda Green Robert Black 8 rows selected. SQL> SQL> drop view EmployeeView; View dropped. SQL> SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL> SQL> SQL>
</source>
User view and object id
<source lang="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> SQL> drop view empView; SQL> drop table emp; SQL> SQL> SQL> SQL> drop type personType; SQL> SQL> drop type addressType; SQL> SQL>
</source>
Use view based on user-defind type
<source lang="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> 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> create view empView (cid, Person) as
2 select cid,personType(Name,addressType(Street, City, State, Zip)) 3 from emp;
SQL> SQL> drop view empView; SQL> drop table emp; SQL> SQL> drop type personType; SQL> SQL> drop type addressType; SQL> SQL>
</source>
Using view to simplify the query
<source lang="sql">
SQL> create table emp
2 ( empno NUMBER(4) constraint E_PK primary key 3 , ename VARCHAR2(8) 4 , init VARCHAR2(5) 5 , job VARCHAR2(8) 6 , mgr NUMBER(4) 7 , bdate DATE 8 , sal NUMBER(6,2) 9 , comm NUMBER(6,2) 10 , deptno NUMBER(2) default 10 11 ) ;
Table created. SQL> insert into emp values(1,"Tom","N", "TRAINER", 13,date "1965-12-17", 800 , NULL, 20); 1 row created. SQL> insert into emp values(2,"Jack","JAM", "Tester",6,date "1961-02-20", 1600, 300, 30); 1 row created. SQL> insert into emp values(3,"Wil","TF" , "Tester",6,date "1962-02-22", 1250, 500, 30); 1 row created. SQL> insert into emp values(4,"Jane","JM", "Designer", 9,date "1967-04-02", 2975, NULL, 20); 1 row created. SQL> insert into emp values(5,"Mary","P", "Tester",6,date "1956-09-28", 1250, 1400, 30); 1 row created. SQL> insert into emp values(6,"Black","R", "Designer", 9,date "1963-11-01", 2850, NULL, 30); 1 row created. SQL> insert into emp values(7,"Chris","AB", "Designer", 9,date "1965-06-09", 2450, NULL, 10); 1 row created. SQL> insert into emp values(8,"Smart","SCJ", "TRAINER", 4,date "1959-11-26", 3000, NULL, 20); 1 row created. SQL> insert into emp values(9,"Peter","CC", "Designer",NULL,date "1952-11-17", 5000, NULL, 10); 1 row created. SQL> insert into emp values(10,"Take","JJ", "Tester",6,date "1968-09-28", 1500, 0, 30); 1 row created. SQL> insert into emp values(11,"Ana","AA", "TRAINER", 8,date "1966-12-30", 1100, NULL, 20); 1 row created. SQL> insert into emp values(12,"Jane","R", "Manager", 6,date "1969-12-03", 800 , NULL, 30); 1 row created. SQL> insert into emp values(13,"Fake","MG", "TRAINER", 4,date "1959-02-13", 3000, NULL, 20); 1 row created. SQL> insert into emp values(14,"Mike","TJA","Manager", 7,date "1962-01-23", 1300, NULL, 10); 1 row created. SQL> SQL> create table departments
2 ( deptno NUMBER(2) constraint D_PK 3 primary key 4 , dname VARCHAR2(10) 5 , location VARCHAR2(8) 6 , mgr NUMBER(4) 7 ) ;
Table created. SQL> SQL> insert into departments values (10,"ACCOUNTING","NEW YORK",7); 1 row created. SQL> insert into departments values (20,"TRAINING", "DALLAS", 4); 1 row created. SQL> insert into departments values (30,"SALES", "CHICAGO", 6); 1 row created. SQL> insert into departments values (40,"HR", "BOSTON", 9); 1 row created. SQL> SQL> create view empdept_v as
2 select e.empno 3 , e.ENAME 4 , e.init 5 , d.dname 6 , d.location 7 , m.ENAME as Designer 8 from emp e 9 join 10 departments d using (deptno) 11 join 12 emp m on (m.empno = d.mgr);
SQL> SQL> select * from empdept_v where Designer = "Chris";
SQL> drop table emp; Table dropped. SQL> drop table departments; Table dropped.
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