Modifying a Table

To modify an existing table, use the ALTER TABLE statement. You can add, modify, or delete columns, change constraints, or rename the table.

Adding a Column:

ALTER TABLE table_name
ADD column_name data_type [constraints];

Example:

ALTER TABLE employees
ADD email VARCHAR(100);

Modifying a Column:

ALTER TABLE table_name
MODIFY column_name new_data_type [constraints];

Example:

ALTER TABLE employees
MODIFY salary DECIMAL(12, 2);

Dropping a Column:

ALTER TABLE table_name
DROP COLUMN column_name;

Example:

ALTER TABLE employees
DROP COLUMN hire_date;

Renaming a Table:

RENAME TABLE old_table_name TO new_table_name;

Example:

RENAME TABLE employees TO staff;