Mysql Alter Multiple Columns

Mysql Alter Multiple Columns is used to modify the table definition and rename the columns name in a table.

Understand with Example

The Tutorial illustrate an example from 'Mysql Alter Multiple Columns'. To grasp this example we create a table employee1.The create table is used to create a table employee1 with respective fieldname and datatype.

Query to Create Table named employee1:

mysql>CREATE TABLE employee1 (              
         ->    Empid int(10),         
         ->    Empname varchar(60),   
         ->    date date 
         ->  );

Query to insert data into Table named employee1:

To insert the records or value into table employee1, we use insert into query that add records or rows into table employee1.

mysql>insert into employee1 values(01,'Girish','2008-12-20');
Query OK, 1 row affected (0.02 sec)

mysql>insert into employee1 values(02,'Komal','2008-12-21');
Query OK, 1 row affected (0.02 sec)

mysql>insert into employee1 values(03,'vineet','2008-12-21');
Query OK, 1 row affected (0.02 sec)

mysql>insert into employee1 values(04,'Amit','2008-12-20');
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)

mysql>insert into employee1 values(02,'Sandeep','2008-12-24');
Query OK, 1 row affected (0.02 sec)

mysql>insert into employee1 values(02,'suman','2008-12-25');
Query OK, 1 row affected (0.02 sec)

mysql>insert into employee1 values(01,'AAA',' 2008-12-03');
Query OK, 1 row affected (0.02 sec)

Query to view data of Table named employee1:

To view the detail of table employee1, we use select query that returns you the detail of table employee1.

mysql> select * from employee1;

Output:-

+-------+---------+------------+
| Empid | Empname | date       |
+-------+---------+------------+
|     1 | Girish  | 2008-12-20 |
|     2 | Komal   | 2008-12-21 |
|     3 | vineet  | 2008-12-21 |
|     4 | Amit    | 2008-12-20 |
|     2 | Komal   | 2008-12-23 |
|     2 | Sandeep | 2008-12-24 |
|     2 | suman   | 2008-12-25 |
|     1 | AAA     | 2008-12-03 |
+-------+---------+------------+
8 rows in set (0.00 sec)

Query to alter multiple column's of Table named employee1:

The Query alter modifies the table employee1 and change the existing column name. The change keyword allows you to rename the existing column name in table employee1..

mysql> alter table employee1
    ->  change Empname Name varchar(100),
    ->   change Dateofbirth DOB date;

Output:-

mysql> select * from employee1;
+-------+---------+------------+
| Empid | Name    | DOB        |
+-------+---------+------------+
| 1     | Girish  | 2008-12-20 |
| 2     | Komal   | 2008-12-21 |
| 3     | vineet  | 2008-12-21 |
| 4     | Amit    | 2008-12-20 |
| 2     | Komal   | 2008-12-23 |
| 2     | Sandeep | 2008-12-24 |
| 2     | suman   | 2008-12-25 |
| 1     | AAA     | 2008-12-03 |
+-------+---------+------------+
8 rows in set (0.00 sec)

Mysql Alter Multiple Columns

Mysql Alter Multiple Columns

Mysql Alter Multiple Columns

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