Introduction to SQL - Part 8 - Views in SQL

Views in SQL

•  Views in SQL are considered as a virtual table. A view also contains rows and columns.
•  To create the view, we can select the fields from one or more tables present in the database.
•  A view can either have specific rows based on certain condition or all the rows of a table.

Creating view

A view can be created using the CREATE VIEW statement. We can create a view from a single table or multiple tables.

• Syntax

            CREATE VIEW view_name AS
            SELECT column1, column2.....
            FROM table_name

            WHERE condition;

• Creating View from a single table

            CREATE VIEW DetailsView AS
            SELECT NAME, ADDRESS
            FROM Student_Details

            WHERE STU_ID < 4;

• 
  Creating View from multiple tables 

• View from multiple tables can be created by simply include multiple tables in the SELECT statement.
• In the given example, a view is created named MarksView from two tables Student_Detail and Student_Marks.

            CREATE VIEW MarksView AS
            SELECT Student_Detail.NAME, Student_Detail.ADDRESS, Student_Marks.MARKS
            FROM Student_Detail, Student_Mark WHERE Student_Detail.NAME =                                                 student_Marks.NAME;

 

            SELECT * FROM MarksView;
 

            DROP VIEW view_name;