Trying to create a table in sql and get this error: "ORA-00907: missing right parenthesis" Please Help.

create table Driver(

Driver_Licence char(15) primary key,

SSN int unique,

First_Name varchar(50) not null,

Last_Name varchar(50),

Birth_Date date DEFAULT '1900-01-01',

Hire_Date date COMMENT 'Hire_Date is the date that employee was first Hired',

State char(2),

INDEX (State),

CONSTRAINT CHK_Driver_HireDate CHECK(Hire_Date > Birth_Date)

);