---

The ALTER TABLE statement is used to add, delete, or modify columns in an existing table.

The ALTER TABLE statement is also used to add and drop various constraints on an existing table.

Syntax:To add a column in a table, use the following syntax:

ALTER TABLE table_name
ADD column_name datatype;

Syntax: ALTER TABLE - DROP COLUMN

ALTER TABLE table_name
DROP COLUMN column_name;

ALTER TABLE - ALTER/MODIFY COLUMN

Syntax: SQL Server / MS Access:

ALTER TABLE table_name
ALTER COLUMN column_name datatype;

Syntax: My SQL / Oracle (prior version 10G):

ALTER TABLE table_name
MODIFY COLUMN column_name datatype;

Syntax: Oracle 10G and later:

ALTER TABLE table_name
MODIFY column_name datatype;

---