Mysql Alter Column

Mysql Alter Column is used to modify table and change the existing column field name.

Mysql Alter Column

Mysql Alter Column

     

Mysql Alter Column is used to modify table and  change the existing column field name.

Understand with Example

The Tutorial illustrate an example from 'Mysql Alter Column'. To understand example ,we create a table 'employee1 ' with the required field name and data type respectively.

 

 

 

 

Query to create table:-

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

Query to insert data into Table named employee1:

The insert into add the 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:

The Query view is used to return the records from 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 for altering the column name of the table employee1:

The Query below is used to modify the table 'employee1' and change the name of column from 'date' to 'Dateofbirth'.

mysql> alter table employee1 change  date Dateofbirth date;
Query OK, 8 rows affected (0.14 sec)
Records: 8  Duplicates: 0  Warnings: 0

Output:-

mysql> select * from employee1;
+-------+---------+-------------+
| Empid | Empname | Dateofbirth |
+-------+---------+-------------+
|     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 (0.36 sec)