Λίστα με τα μαθήματα Συνδεθείτε

Information

Author(s) Quentin Cappart
Deadline Καμία προθεσμία
Submission limit No limitation

Συνδεθείτε

Συνδεθείτε

Compréhension des mots clefs (opérations d'ensemble)

Parmi les propositions suivantes, trouvez celle donnant une description correcte des mots-clefs (ou requêtes) suivants.

Question 1: 
select name
from student
where dept_name = 'Biology'
union
select name
from instructor
where dept_name = 'Biology';
Question 2: 
select dept_name
from student
union all
select dept_name
from instructor;
Question 3: 
select dept_name
from student
intersect
select dept_name
from instructor;
Question 4: 
select course_id
from course
where dept_name = 'Biology'
except
select course_id
from prereq;
Question 5: 
select ID
from student
intersect
select ID
from instructor;
Question 6: 
select name, dept_name
from student
union
select name
from instructor;