Download Tables in the Oracle Database

Chapter Nine
Data Manipulation Language (DML)
Views

Objectives




Definition
Creating views
Retrieve data from a view
Drop a view
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VIEWS
DATABASE OBJECTS
1-TABLE
2-VIEW
-What is a view?
-Why using a view?
Restrict database access.
Make complex queries easy.
Represent data from different tables
Represent different Views of the same
data.
2
VIEWS
DATABASE OBJECTS
CREATE VIEW
COSCStudent
AS
SELECT
ID, Name, GPA
FROM
Student
WHERE
Major=‘COSC’;
DESCRIBE COSCStudent;
3
Practice:
Create a view called Customer_v with the
attributes:
-Customer
-Customer
-Customer
-Customer
-Customer
-Customer
number
last name
Street
City
State
zip code
4
Practice:
Create a view for customer sales person called
Cust_Sale_v with the attributes:
-Customer number
-Customer last name
-Sales Rep Number
-Sales Person First Name
-Sales Person Last Name
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VIEWS
DATABASE OBJECTS
Aliases Column Name:
CREATE VIEW
COSCStudent
AS
SELECT
ID COSCid,
name COSCName,
GPA
FROM
Student
WHERE
Major=‘COSC’;
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VIEWS
DATABASE OBJECTS
Retrieving Data from View:
SELECT
*
FROM
COSCStudent;
SELECT
FROM
COSCid, COSCname
COSCStudent;
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Practice:
Display all the fields in Cust_Sale_v
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VIEWS
DATABASE OBJECTS
Example:
CREATE VIEW COSCData
(minsal, maxsal, avesal)
AS
SELECT
MIN(salary), MAX (salary),
AVG (salary)
FREOM
faculty
WHERE
dept =‘COSC’;
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Practice:
Create a view called Cust_v with the attributes:
-Customer number
-Customer name (Last, First)
-Customer Address (Street, city, state, zip)
-Customer balance
-Customer credit limit
-Sales Rep Number
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VIEWS
DATABASE OBJECTS
Removing a View:
DROP VIEW majors;
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Practice:
Remove the view Cust_v
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Practice:
Create a view using a sub-query.
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