SQL - ALTER Statement

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.

ALTER TABLE - ADD Column To add a column in a table:

ALTER TABLE table_name
ADD column_name datatype;

ALTER TABLE - DROP COLUMN To delete a column in a table:

ALTER TABLE table_name
DROP COLUMN column_name;

ALTER TABLE - ALTER/MODIFY COLUMN To change the data type of a column in a table:

ALTER TABLE table_name
MODIFY COLUMN column_name datatype;