[an error occurred while processing this directive]

Mysql Alter Table

[an error occurred while processing this directive]

                         

Mysql Alter Table is used to redefine the existing table.

Understand with Example

The Tutorial illustrate an example from 'Mysql Alter Table'. To grasp this example we create a table 'employees'. The create table statement is used to create a table 'employees' with different fieldname and datatype respectively. The table have a Primary Key column 'empid'.

Query to create table:

CREATE TABLE employees ( 
            ->Empid int(10),  
            ->Empname varchar(60),
             ->date date 
	     ->PRIMARY KEY(Empid)  
           ->);

Query to insert data into Table named employees:

The Query insert into add the records or rows into 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)

Query to view data of  Table named employees:

To view the detail of table 'employees' we use select query that returns the detail of table 'employees'.

mysql> select * from employees;
[an error occurred while processing this directive]

Output:-

+-------+---------+------------+
| Empid | Empname | date       |
+-------+---------+------------+
|     1 | Girish  | 2008-12-22 |
|     2 | Komal   | 2008-12-23 |
+-------+---------+------------+
2 rows in set (0.00 sec)

Query to alter Table named employees by adding column named city:

The Query Alter is used to modify the table 'employees' and add keywords is used to add the column name 'city' to the existing table.

mysql> alter table employees
    -> add column city varchar(30);
Query OK, 2 rows affected (0.13 sec)
Records: 2  Duplicates: 0  Warnings: 0

Output:-

mysql> select * from employees;
+-------+---------+------------+------+
| Empid | Empname | date       | city |
+-------+---------+------------+------+
|     1 | Girish  | 2008-12-22 | NULL |
|     2 | Komal   | 2008-12-23 | NULL |
+-------+---------+------------+------+
2 rows in set (0.02 sec)
[an error occurred while processing this directive]

                         

[an error occurred while processing this directive]