As you use the table, you may discover that it’s not everything you need it to be. You can use the ALTER TABLE statement to change the table by adding, changing, or deleting a column in the table. Besides tables, you can also ALTER columns and domains.

•    The ALTER TABLE statement is used to add, delete, or modify columns in an existing table. It is also used to add and drop various constraints on an existing table.

ALTER TABLE - ADD Column

                       ALTER TABLE table_name

                      ADD column_name datatype;

ALTER TABLE - DROP COLUMN

                    ALTER TABLE table_name

                    DROP COLUMN column_NAME;

ALTER TABLE - RENAME COLUMN

                  ALTER TABLE table_name

                 RENAME COLUMN old_name to new)