Oracle Database Administration: The Essential Refe

column_constraint_clause

The following is the syntax for the column_constraint_clause in the CREATE TABLE statement. See the description of the keywords in the table_constraint_clause section.

{
[NULL | NOT NULL] |
[UNIQUE | PRIMARY KEY] |
[FOREIGN KEY (column[, column ...])]
[REFERENCES [schema.]table_name[(column)] [ON DELETE CASCADE] ]
[CHECK (condition)]
}
[USING INDEX 
    [PCTFREE integer]
    [PCTUSED integer]
    [INITRANS integer]
    [MAXTRANS integer] 
    [TABLESPACE tablespace_name]
    [STORAGE (
        [INITIAL integer [K | M]]
        [NEXT integer [K | M]]
        [MINEXTENTS integer [K | M]] 
        [MAXEXTENTS {integer | UNLIMITED}]
        [PCTINCREASE integer]
        [FREELISTS integer]
        [FREELIST GROUPS integer]
        )
    [NOSORT]
    [LOGGING | NOLOGGING]
]
[EXCEPTIONS INTO [schema.]table_name]
[{ENABLE [VALIDATE  | NOVALIDATE] | DISABLE} ]
[[NOT] DEFERRABLE [INITIALLY {IMMEDIATE | DEFERRED}] ]
[[INITIALLY {IMMEDIATE | DEFERRED}] [[NOT] DEFERRABLE] ]