Alter table insert new column mysql

To add a new column to an existing 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.

If you want to add a column with a default value, you can use the following syntax:

ALTER TABLE table_name
ADD COLUMN new_column_name data_type DEFAULT default_value;

For example, to add a new column called country with a data type of varchar and a default value of 'USA', you would use the following command:

ALTER TABLE employees
ADD COLUMN country varchar(50) DEFAULT 'USA';

This will add a new column called country with a data type of varchar(50) and a default value of 'USA' to the employees table.

If you want to add a column with a specific length or precision, you can use the following syntax:

ALTER TABLE table_name
ADD COLUMN new_column_name data_type(length|precision);

For example, to add a new column called phone_number with a data type of varchar and a length of 20, you would use the following command:

ALTER TABLE employees
ADD COLUMN phone_number varchar(20);

This will add a new column called phone_number with a data type of varchar and a length of 20 to the employees table.

Note that you can only add a column to the end of the table, not in the middle. If you want to add a column in a specific position, you will need to use a different approach, such as creating a new table with the desired structure and then copying the data from the old table to the new table.