SQL ALTER TABLE Keyword

ALTER TABLE

The ALTER TABLE command adds, deletes, or modifies columns in a table.

The ALTER TABLE command also adds and deletes various constraints in a table.

The following SQL adds an "Email" column to the "Customers" table:

ALTER TABLE Customers
ADD Email varchar(255);

The following SQL deletes the "Email" column from the "Customers" table:

ALTER TABLE Customers
DROP COLUMN Email;