1. 1 Chapter Nine Data Manipulation Language (DML) Views Objectives Definition Creating views Retrieve data from a view Drop a view

2. 2 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.

3. 3 CREATE VIEW COSCStudent AS SELECT ID, Name, GPA FROM Student WHERE Major=‘COSC’; DESCRIBE COSCStudent; VIEWS DATABASE OBJECTS

4. 4 Practice:  Create a view called Customer_v with the attributes: -Customer number -Customer last name -Customer Street -Customer City -Customer State -Customer zip code

5. 5 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

6. 6 Aliases Column Name: CREATE VIEWCOSCStudent AS SELECTID COSCid, name COSCName, GPA FROMStudent WHEREMajor=‘COSC’; VIEWS DATABASE OBJECTS

7. 7 Retrieving Data from View: SELECT* FROMCOSCStudent; SELECTCOSCid, COSCname FROMCOSCStudent; VIEWS DATABASE OBJECTS

8. 8 Practice:  Display all the fields in Cust_Sale_v

9. 9 Example: CREATE VIEW COSCData (minsal, maxsal, avesal) AS SELECTMIN(salary), MAX (salary), AVG (salary) FREOMfaculty WHEREdept =‘COSC’; VIEWS DATABASE OBJECTS

10. 10 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

11. 11 Removing a View: DROP VIEW majors; VIEWS DATABASE OBJECTS

12. 12 Practice:  Remove the view Cust_v

13. 13 Practice:  Create a view using a sub-query.