Alter table with new column mysql

To add a new column to a table in MySQL, you can use the following SQL command:

ALTER TABLE table_name
ADD COLUMN new_column_name data_type;

Here:

• table_name is the name of the table you want to modify.
• new_column_name is the name of the new column you want to add.
• data_type is the data type of the new column (e.g. int, varchar, datetime, etc.).

For example, to add a new column called age with a data type of int to a table called employees, you would use the following command:

ALTER TABLE employees
ADD COLUMN age int;

This will add a new column called age with a data type of int to the employees table.

You can also specify additional options when adding a new column, such as:

• DEFAULT value: specifies the default value for the new column.
• NULL or NOT NULL: specifies whether the new column can contain null values.
• UNIQUE or NOT UNIQUE: specifies whether the new column can have duplicate values.

For example:

ALTER TABLE employees
ADD COLUMN age int DEFAULT 25 NOT NULL;

This will add a new column called age with a data type of int, a default value of 25, and not allowing null values.

Note: You can only add a new column to the end of the table, you can't add it in the middle of the table.

Also, you can use ALTER TABLE table_name ADD COLUMN new_column_name AFTER existing_column_name to add a new column after a specific existing column.

For example:

ALTER TABLE employees
ADD COLUMN new_column_name int AFTER age;

This will add a new column called new_column_name with a data type of int after the age column.