SQL Alter View

sql alter view

SQL Alter View

SQL Alter View

     

View is a virtual and imaginary table come out as result -set of an SQL statement. A virtual table contains rows and columns, as same as real table. In SQL Alter View is used to modify a previous created view. The advantage of Alter View hardly any effect on dependent procedure, trigger and change permissions.

Understand with Example

The Tutorial illustrates an example from SQL Alter View. In this Tutorial, we want to describe you how to alter a created view. For, this we create a table 'Stu_Table' using create statement. The insert into add the records or rows to the created table'Stu_Table'.The select statemet  return you all the record added by the insert into statement. 

Create Table Stu_Table

create table Stu_Table(Stu_Id integer(2), Stu_Name varchar(15), Stu_Class  varchar(10))

Insert data into Stu_Table

insert into Stu_Table values(1,'Komal',10);
insert into Stu_Table values(2,'Ajay',10);
insert into Stu_Table values(3,'Rakesh',10);
insert into Stu_Table values(4,'Bhanu',10);
insert into Stu_Table values(5,'Santosh',10);
insert into Stu_Table values(6,'Tanuj',10);

Stu_Table

Stu_Id Stu_Name Stu_Class
1 Komal 10
2 Ajay 10
3 Rakesh 10
4 Bhanu 10
5 Santosh 10
6 Tanuj 10

Create View

Now we create a view of table 'Stu_Table'. The view "Stu_View" lists all the field from the "Stu_View" table. The view can be created with the help of given SQL Query. 

CREATE VIEW Stu_View( Stu_id, Stu_Name, Stu_Class)
AS SELECT  Stu_id, Stu_name, Stu_class 
FROM Stu_Table

View Stu_View

You can see the created view "Stu_View" using View Stu_View statement.

Stu_Id Stu_Name Stu_Class
1 Komal 10
2 Ajay 10
3 Rakesh 10
4 Bhanu 10
5 Santosh 10
6 Tanuj 10

Alter View

The Alter View modify the existing created view Stu_View. The ALTER VIEW  statement is used to modify the Stu_View enlisted all the list of field selected in select query. The WHERE clause restrict the select query and return you the record based upon condition whose stu_Id is less than equal to'5'.

ALTER VIEW Stu_View(Stu_id,Stu_Name,Stu_Class)
AS SELECT  stu_id, stu_name, stu_class 
FROM Stu_Table where Stu_Id <=5

View  Stu_View

Stu_Id Stu_Name Stu_Class
1 Komal 10
2 Ajay 10
3 Rakesh 10
4 Bhanu 10
5 Santosh 10