Question

I have three tables:

students, modules and students_modules (which is a linking table). What I am trying to do id selecting the modules associated with a particular student. I know that this is wrong but what I’m trying to do is something like this:

SELECT id, name 
FROM modules 
WHERE id = (SELECT moduleID FROM students_modules WHERE studentID = '123')

So could any one help me please.

Answer 1

Use JOIN to link the three tables with each others:

SELECT 
  s.StudentName,
  m.Id,
  m.Name AS ModuleName
FROM modules                AS m
INNER JOIN students_modules AS sm ON m.id         = sm.moduleID
INNER JOIN students         AS  s ON sm.studentID = s.id
WHERE WHERE ms.studentID = '123';