Which medication has brand X?
select * from medication where brand = "X"
Find the physicians who prescribe this medication.
select distinct t1.physician from prescribes as t1 join medication as t2 on t2.code = t1.medication where t2.brand = "X"
What are their name and position?
select distinct t1.name, t1.position from physician as t1 join prescribes as t2 on t1.employeeid = t2.physician join medication as t3 on t3.code = t2.medication where t3.brand = "X"