Mysql Alter View

View is a virtual table, act like a table but actually it does not
contain data. The view is the outcome result set of a SELECT statement. A
view include rows and columns from one or more than one tables. A View
is a query that is stored as an object. It is simply a subset of table's
column. View ensures security mechanism to the table. Alter View is used to
modify and change the definition of view.
Query to create table:
The create table employee is used to create a
table employee with a primary key (Empid).
CREATE TABLE `employees` (
->Empid int(10),
->Empname varchar(60),
->date date
->PRIMARY KEY(Empid)
->);
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Query to insert data into Table named employees:
The Query insert into is used to add the records
or rows to the table 'employees'.
mysql>insert into employees values(01,'Girish','2008-12-22');
Query OK, 1 row affected (0.02 sec)
mysql>insert into employee1 values(02,'Komal','2008-12-23');
Query OK, 1 row affected (0.02 sec)
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Query to view data of Table named employees:
To view the detail from table 'employees' we run the
select Query that return you the records from table 'employees'.
mysql> select * from employees;
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Output:-
+-------+---------+------------+
| Empid | Empname | date |
+-------+---------+------------+
| 1 | Girish | 2008-12-22 |
| 2 | Komal | 2008-12-23 |
+-------+---------+------------+
2 rows in set (0.00 sec)
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Query to create view of Table named employees:
The Query below create a 'view Emp' and return the
select records from table 'Emp'.
mysql> create view Emp
-> as Select employees.empname,employees.date
-> from employees;
Query OK, 0 rows affected (0.00 sec)
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Query to see the records in view:
To see the detail of table emp view , we use
select Query that return the detail of emp.
mysql> select * from emp;
+---------+------------+
| empname | date |
+---------+------------+
| Girish | 2008-12-22 |
| Komal | 2008-12-23 |
+---------+------------+
2 rows in set (0.00 sec)
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Query to alter view:
The Query alter view is used to modify the table
view emp and include all the records from table 'emp'.
mysql> alter view emp as select * from employees;
Query OK, 0 rows affected (0.00 sec)
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Query to see the data of the altered view:-
mysql> select * from emp;
+-------+---------+------------+
| Empid | Empname | date |
+-------+---------+------------+
| 1 | Girish | 2008-12-22 |
| 2 | Komal | 2008-12-23 |
+-------+---------+------------+
2 rows in set (0.00 sec)
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