Here is the SQL to create the schema for this example. For anyone who wants to try the solution from @Eric.
create table markdetails (studid, subjectid, marks);
create table student_info (studid, name);
insert into markdetails values('A1', 3, 50);
insert into markdetails values('A1', 4, 60);
insert into markdetails values('A1', 5, 70);
insert into markdetails values('B1', 3, 60);
insert into markdetails values('B1', 4, 80);
insert into markdetails values('C1', 5, 95);
insert into student_info values('A1', 'Raam');
insert into student_info values('B1', 'Vivek');
insert into student_info values('C1', 'Alex');
Here is an alternative solution using case
with group by
.
select
si.studid,
si.name,
sum(case when md.subjectid = 3 then md.marks end) subjectid_3,
sum(case when md.subjectid = 4 then md.marks end) subjectid_4,
sum(case when md.subjectid = 5 then md.marks end) subjectid_5
from student_info si
join markdetails md on
md.studid = si.studid
group by si.studid, si.name
;
For comparison, here is the same select statement from @Eric’s solution:
select
u.stuid,
u.name,
s3.marks as subjectid_3,
s4.marks as subjectid_4,
s5.marks as subjectid_5
from
student_info u
left outer join markdetails s3 on
u.stuid = s3.stuid
and s3.subjectid = 3
left outer join markdetails s4 on
u.stuid = s4.stuid
and s4.subjectid = 4
left outer join markdetails s5 on
u.stuid = s5.stuid
and s5.subjectid = 5
;