Syntax

ALTER TABLE table_name [add_clause] [drop_clause] [rename_clause]

where:

table_name
specifies an existing local table.
add_clause
specifies a column or constraint to be added to the table. See "Add Clause: Columns" and "Add Clause: Constraints" for a complete explanation.
drop_clause
specifies a column or constraint to be dropped from the table. See "Drop Clause: Columns" and "Drop Clause: Constraints" for a complete explanation.
rename_clause
specifies a new name for the table. See "Rename Clause" for a complete explanation.