Oracle SQL/PLSQL Section 2.4: Create or replace a view

Oracle SQL/PLSQL Section 2.4: Create or replace a view

 In this example, we are going to create a view. A view is mostly used to simply fetch data from multiple tables.

 Example 1: 

View with a select on one table.

 CREATE OR REPLACE VIEW LessonView 

AS 

 SELECT  L.* 

 FROM Lesson L;

 Example 2: 

 View with a select on multiple tables.

CREATE OR REPLACE VIEW ClassRoomLessonView 

AS SELECT C.Id, C.Name, L.Subject, L.Teacher 

 FROM ClassRoom C, Lesson L 

 WHERE C.Id = L.ClassRoomId;

 To call this views in a query you can use a select statement.

SELECT * FROM LessonView; 

SELECT * FROM ClassRoomLessonView;