ALTER VIEW statement : Alter View « View « MySQL Tutorial

1. MySQL Tutorial
2. View
3. Alter View

The ALTER VIEW statement is the same as the CREATE statement, except for the omission of the OR REPLACE option.

The ALTER VIEW statement does the same thing as CREATE OR REPLACE.

The full ALTER statement looks like this:

ALTER [<algorithm attributes>] VIEW [<database>.]< name> [(<columns>)] AS
<SELECT statement> [<check options>]

mysql>
mysql> CREATE TABLE Employee(
    ->     id            int,
    ->     first_name    VARCHAR(15),
    ->     last_name     VARCHAR(15),
    ->     start_date    DATE,
    ->     end_date      DATE,
    ->     salary        FLOAT(8,2),
    ->     city          VARCHAR(10),
    ->     description   VARCHAR(15)
    -> );
Query OK, 0 rows affected (0.02 sec)

mysql>
mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->              values (1,'Jason',    'Martin',  '19960725',  '20060725', 1234.56, 'Toronto',  'Programmer');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(2,'Alison',   'Mathews',  '19760321', '19860221', 6661.78, 'Vancouver','Tester');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(3,'James',    'Smith',    '19781212', '19900315', 6544.78, 'Vancouver','Tester');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(4,'Celia',    'Rice',     '19821024', '19990421', 2344.78, 'Vancouver','Manager');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(5,'Robert',   'Black',    '19840115', '19980808', 2334.78, 'Vancouver','Tester');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(6,'Linda',    'Green',    '19870730', '19960104', 4322.78,'New York',  'Tester');
Query OK, 1 row affected (0.02 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(7,'David',    'Larry',    '19901231', '19980212', 7897.78,'New York',  'Manager');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> insert into Employee(id,first_name, last_name, start_date, end_Date,   salary,  City,       Description)
    ->               values(8,'James',    'Cat',     '19960917',  '20020415', 1232.78,'Vancouver', 'Tester');
Query OK, 1 row affected (0.00 sec)

mysql>
mysql> select * from Employee;
+------+------------+-----------+------------+------------+---------+-----------+-------------+
| id   | first_name | last_name | start_date | end_date   | salary  | city      | description |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
|    1 | Jason      | Martin    | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto   | Programmer  |
|    2 | Alison     | Mathews   | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester      |
|    3 | James      | Smith     | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester      |
|    4 | Celia      | Rice      | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager     |
|    5 | Robert     | Black     | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester      |
|    6 | Linda      | Green     | 1987-07-30 | 1996-01-04 | 4322.78 | New York  | Tester      |
|    7 | David      | Larry     | 1990-12-31 | 1998-02-12 | 7897.78 | New York  | Manager     |
|    8 | James      | Cat       | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester      |
+------+------------+-----------+------------+------------+---------+-----------+-------------+
8 rows in set (0.00 sec)

mysql>
mysql>
mysql>
mysql> Create VIEW myView (id,first_name,city)
    -> AS SELECT id, first_name, city FROM employee;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> select * from myView;
+------+------------+-----------+
| id   | first_name | city      |
+------+------------+-----------+
|    1 | Jason      | Toronto   |
|    2 | Alison     | Vancouver |
|    3 | James      | Vancouver |
|    4 | Celia      | Vancouver |
|    5 | Robert     | Vancouver |
|    6 | Linda      | New York  |
|    7 | David      | New York  |
|    8 | James      | Vancouver |
+------+------------+-----------+
8 rows in set (0.00 sec)

mysql>
mysql>
mysql> ALTER VIEW myView (id,first_name,city)
    -> AS SELECT id, upper(first_name), city FROM employee;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql> select * from myView;
+------+------------+-----------+
| id   | first_name | city      |
+------+------------+-----------+
|    1 | JASON      | Toronto   |
|    2 | ALISON     | Vancouver |
|    3 | JAMES      | Vancouver |
|    4 | CELIA      | Vancouver |
|    5 | ROBERT     | Vancouver |
|    6 | LINDA      | New York  |
|    7 | DAVID      | New York  |
|    8 | JAMES      | Vancouver |
+------+------------+-----------+
8 rows in set (0.02 sec)

mysql>
mysql> drop view myView;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>
mysql>
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.00 sec)

mysql>