Create students-and-examinations.sql

Author: kamyu104

MySQL/students-and-examinations.sql

@@ -0,0 +1,16 @@
+# Time:  O((m * n) * log(m * n))
+# Space: O(m * n)
+
+SELECT a.student_id, 
+       a.student_name, 
+       b.subject_name, 
+       Count(c.subject_name) AS attended_exams 
+FROM   students AS a 
+       CROSS JOIN subjects AS b 
+       LEFT JOIN examinations AS c 
+              ON a.student_id = c.student_id 
+                 AND b.subject_name = c.subject_name 
+GROUP  BY a.student_id, 
+          b.subject_name
+ORDER  BY a.student_id, 
+          b.subject_name;