Question

say we have a schedule table like this

course    day

  A       MONDAY

  A       WEDNESDAY

  B       MONDAY

  C       WEDNESDAY

my question is , how do i select the course whose day is on both Monday and Wednesday?

thanks

Answer 1

Fiddle link for sample query execution

create table schedule (course varchar2(10),day varchar2(20));
insert into schedule values('A','MONDAY');
insert into schedule values('A','WEDNESDAY');
insert into schedule values('B','MONDAY');
insert into schedule values('C','WEDNESDAY');

select s1.course
 from 
  schedule s1,schedule s2 
 where 
  s1.course=s2.course 
 AND
  s1.day='MONDAY'
 AND
  s2.day='WEDNESDAY';

OUTPUT

| COURSE |
----------
|      A |