Write a query to display name
of each student, and the difference between the marks the student scored and the average marks of the students enrolled in the same course as the student
. Set the 2 respective headers as name
and deviation
.
For example, if Clark
has scored 85
marks, and is enrolled in Java
, where the average marks of students enrolled in Java
is 55
, then under the header deviation
, the results should show 85 - 55 = 30
for Clark
Note:
Even if you find other ways of doing it, try doing it using a correlated subquery in a SELECT clause, just for the sake of your better understanding of the topic.
Hint:
In addition to be valid as an individual field in a SELECT clause, the results from a subquery can also serve as part of a field, as either sides of an arithmetic/boolean operator, given the result from the subquery is a single value.