diff --git a/.DS_Store b/.DS_Store new file mode 100644 index 0000000..49c341a Binary files /dev/null and b/.DS_Store differ diff --git a/answers/exercise1.sql b/answers/exercise1.sql index e69de29..93032d7 100644 --- a/answers/exercise1.sql +++ b/answers/exercise1.sql @@ -0,0 +1,4 @@ +SELECT * +FROM Enrolments +LEFT JOIN Students +ON Enrolments.StudentID=Students.StudentID; diff --git a/answers/exercise2.sql b/answers/exercise2.sql index e69de29..9dfb272 100644 --- a/answers/exercise2.sql +++ b/answers/exercise2.sql @@ -0,0 +1,4 @@ +SELECT * +FROM Enrolments +INNER JOIN Students +ON Enrolments.StudentID=Students.StudentID \ No newline at end of file diff --git a/answers/exercise3.sql b/answers/exercise3.sql index e69de29..19d13ac 100644 --- a/answers/exercise3.sql +++ b/answers/exercise3.sql @@ -0,0 +1,4 @@ +SELECT * +FROM Enrolments +RIGHT JOIN Students +ON Enrolments.StudentID=Students.StudentID; \ No newline at end of file diff --git a/answers/exercise4.sql b/answers/exercise4.sql index e69de29..366064a 100644 --- a/answers/exercise4.sql +++ b/answers/exercise4.sql @@ -0,0 +1,3 @@ +SELECT COUNT (StudentID) AS NumberOfStudents, Country +FROM Students +GROUP BY Country; \ No newline at end of file diff --git a/answers/exercise5.sql b/answers/exercise5.sql index e69de29..a7f9d95 100644 --- a/answers/exercise5.sql +++ b/answers/exercise5.sql @@ -0,0 +1,4 @@ +SELECT COUNT (StudentID) AS NumberOfStudents, Country +FROM Students +GROUP BY Country +ORDER BY COUNT (StudentID) DESC; \ No newline at end of file diff --git a/answers/exercise6.sql b/answers/exercise6.sql index e69de29..07bf7ef 100644 --- a/answers/exercise6.sql +++ b/answers/exercise6.sql @@ -0,0 +1,5 @@ +SELECT COUNT (StudentID) AS NumberOfStudents, Country +FROM Students +GROUP BY Country +HAVING COUNT (StudentID) > 10 +ORDER BY COUNT(StudentID) DESC; \ No newline at end of file