An ALTER TABLE statement changes the properties of a base table (see
Table).Syntax
<alter_table_statement> ::=
ALTER TABLE <table_name> <add_definition>
| ALTER TABLE <table_name> <drop_definition>
| ALTER TABLE <table_name> <alter_definition>
| ALTER TABLE <table_name> <column_change_definition>
| ALTER TABLE <table_name> <modify_definition>
| ALTER TABLE <table_name> <referential_constraint_definition>
| ALTER TABLE <table_name> DROP FOREIGN KEY <referential_constraint_name>
| ALTER TABLE <table_name> <sample_definition>
Explanation
The table name must be the name of an existing base table. The table must not be a temporary base table. The current user must have the ALTER privilege for the specified table.