É necessário criar uma tabela EMPLOYEES na qual os valores das colunas EMPLOYEES_ID e LOGIN_ID têm de ser únicos e não nulos. (Escolha dois.) Quais são as duas instruções SQL que criariam a tabela necessária?
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,login_id NUMBER,employee_name VARCHAR2(25),hire_date DATE,CONSTRAINT emp_id_pk PRIMARY KEY (employee_id, login_id));
C. CREATE TABLE employees(employee_id NUMBER CONSTRAINT emp_id_pk PRIMARY KEY, Login_id NUMBER UNIQUE, Employee_name VARCHAR2(25),Hire_date DATE);
D. 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));
E. 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));