Sunday, February 16, 2020

View in SQL By Sagar Jaybhay 2020

In this article Sagar Jaybhay explain what is View. What is the use of View. what is the advantages of views in SQL server.





View





The view is saved SQL query or we can call it a virtual table.









View In SQL 1
View In SQL 1








We have these 2 tables and by joining these 2 tables we want to output.









View In SQL 2
View In SQL 2








By joining these 2 tables we get the above result. Now we want to create a view, like other create statement like create a table, create procedure we have to create view statement





Below is a query for creating a view





create view empwithdepartment
as
select e.EmpID,e.full_name,e.Salary,e.Gender,d.Department_Name from Employee as e
join Department as d on d.DepartmentID=e.DepartmentID;








View In SQL 3
View In SQL 3








To find a view in the database refer below image









How to find view
How to find view








If you check the above query it just selects query and if you want to get data from the view you will able to treat it as a table and simple select * from view_name; by using this you can get data.





View doesn’t store any data and it is just saved select query.









Advantages of views









  1. It is used to reduce the complexity of database schema
  2. It provides a mechanism to implement column level and row-level security means if you want to give access to certain users with a limited number of rows and columns then put your query in view and given that view name to end-user so that he performs the operation on that considering this is a table. By doing this end-user doesn’t know the underlying base table.
  3. It Is used to present aggregated data or detailed data.








To alter view you can use alter view syntax





Alter view view_name
As
- your query syntax here








To drop the view you can use









Drop view view_name;













GitHub : https://github.com/Sagar-Jaybhay






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