I need help with this query in sql. here are the tables students(sid,name,age,gp
ID: 3807186 • Letter: I
Question
I need help with this query in sql.
here are the tables
students(sid,name,age,gpa) // sid is the primary key
courses(cid,deptid, description) // cid,deptid is the primary key
professors(ssn,name,address,phone,deptid) // ssn is the primary key
enrollment(sid,cid,section,grade) cid makes reference to the courses table. // sid, cid, and section is the primary key
teaches(cid,section,ssn). cid, section makes reference to the enrollment table // cid, section is the primary key
a. On average what percentage of students fail a course? (total number of students that failed a course / total number of enrolled students). A student failed the course if he/she gets a 'D' or an 'F'.
Explanation / Answer
please use the below query to get Student Failed Percentage
DECLARE @NoFailedStudent INT
DECLARE @NoEnrolledStudent INT
Select @NoEnrolledStudent = count(distinct sid) From enrollment
Select @NoFailedStudent = count(distinct sid) From enrollment Where grade IN ('D','F')
Select (@NoFailedStudent/@NoEnrolledStudent)*100 AS StudentFailedPercentage