using this shcma answer:

To add constraint on column course_level that checks that the level is between 1 to 5 :

a.

Alter table courses add constraint_S check (course_level between 1 and 5) ;

b.

Alter table courses add constraint S check (course_level >=1 and

c.

Alter table courses add constraint con check (course_level >=1 and course_level

d.

Alter table courses modify constraint constraint_S check (course_level between 1 and 5) ;

To add new Teacher : insert into teachers(teacher_id) values(15154);

a.

The entry added to table teachers.

b.

Not enough values.

c.

unique constraint.

d.

Cant insert null to teacher name .

Clear my choice

Display student whose id is equal to that of any students in the majors 124 or 125.

a.

SELECT full_name, id, major_id FROM students WHERE id= ALL (SELECT id FROM students WHERE major_id in(124,125));

b.

SELECT full_name, id, major_id FROM students WHERE id= ANY (SELECT id FROM students WHERE major_id in(124,125));

c.

SELECT full_name, id, major_id FROM students WHERE id= (SELECT id FROM students WHERE major_id in(124,125));

d.

SELECT full_name, id, major_id FROM students WHERE id= (SELECT id FROM students WHERE major_id=124 and major_id=125);

Exam_results Majors Major_id: number(3) Major_name: varchar2(50) Department_name: varchar2(50) Faculty:varchar2(50) Student_id: number(10) Course_id: number(10) Exam_name: varchar2(50) Max_mark: number(5,2) Mark:number(5,2) courses Students Course_id: number(10) Course_name:varchar21 100) Credit_hours:number(2) Course_level:number(2) Teachers Teacher_id: number(5) Teacher_name:varchar2 (50) Department_name:varc har2(10) ID: Number(10) Full_name: Varchar2(50) Address: varchar2(50) Bd:date Gender: char(1) Major_id: number(3) Registration_date: date Semester Semester_id: number(5) Start_date: date End_date: date Description:varchar2(50) Registration Student_id: number(10) Course_id: number(10) Semester_id: number(5) Teacher_id: number(5) Result_number: number(5,2) Result_letter: char(1)