你可能感興趣的試題

A. SELECT employee_id, salary, tax_percent   FROM employees e, tax t   WHERE e.salary BETWEEN t.min_salary AND t.max_salary;
B. SELECT employee_id, salary, tax_percent   FROM employees e, tax t   WHERE e.salary > t.min_salary, tax_percent
C. SELECT employee_id, salary, tax_percent   FROM employees e, tax t   WHERE MIN(e.salary) = t.min_salary   AND MAX(e.salary) = t.max_salary
D. You cannot find the information because there is no common column between the two tables.

A. ALTER TABLE students ADD PRIMARY KEY _ id;
B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);
C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;
D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);