A. CREATE TABLE employees
(employee_id NUMBER,
Login_id NUMBER,
Employee_name VARCHAR2(100),
Hire_date DATE,
CONSTRAINT emp_id_ukUNIQUE (employee_id, login_id));

B. CREATE TABLE employees
(employee_id NUMBER CONSTRAINT emp_id_pk PRIMARY KEY,
Login_id NUMBER UNIQUE,
Employee_name VARCHAR2(25),
Hire_date DATE);

C. CREATE TABLE employees
(employee_id NUMBER CONSTRAINT emp_id_nn NOT NULL,
Login_id NUMBER CONSTRAINT login_id_nn NOT NULL,
Employee_name VARCHAR2(100),
Hire_date DATE,
CONSTRAINT emp_id_ukUNIQUE (employee_id, login_id));

D. CREATE TABLE employees
(employee_id NUMBER,
login_id NUMBER,
employee_name VARCHAR2(25),
hire_date DATE,
CONSTRAINT emp_id_pk PRIMARY KEY (employee_id, login_id));

E. CREATE TABLE employees
(employee_id NUMBER,
Login_id NUMBER,
Employee_name VARCHAR2(100),
Hire_date DATE,
CONSTRAINT emp_id_uk UNIQUE (employee_id, login_id);
CONSTRAINT emp_id_nn NOT NULL (employee_id, login_id));