15> CREATE TABLE employee
16> (
17> emp_id int NOT NULL PRIMARY KEY,
18> emp_name varchar(30) NOT NULL,
19> mgr_id int NOT NULL REFERENCES employee(emp_id)
20> )
21> GO
1>
2> ALTER TABLE employee
3> ALTER COLUMN emp_name varchar(50)
4> GO
1>
2> drop table employee;
3> GO
1>