Creating SELECT query between 3 tables

Question

Hi there,
Im trying to create a SELECT query between 3 tables and it is driving me round the bend.
I have 3 tables connected together which are:
MODUL
modulid
modulname
modulevel
STUDENT
studentid
surname
inits
s e x
phone
email
logon
STUDREGOCCUR
modulid
acyear
semester
occletter
studentid
result
I want to select the fields surname, inits, studentid from the STUDENT table, modulname from the MODUL table and result from my STUDREGOCCUR table that is NOT NULL.
I have tried SELECT STUDENT.STUDENTID, STUDENT.INITS, STUDENT.SURNAME, MODUL.MODULNAME, STUDREGOCCUR.RESULT WHERE STUDREGOCCUR.RESULT IS NOT NULL;
I have also tried many other ways and done research hwich hasnt really helped me unfortunately.
Im quite new to SELECT queries and im not sure where im going wrong, i would greatly appreciate if someone could help me solve my problem.
Thanks for the help :)
Edited by: user633643 on 06-Dec-2008 08:09

Answer 1

If you want data from multiple tables you would need to perform a join. The general form would be:
select t1.cola, t2.col2, t3.col.x
from table_a a, table_b b, table_c c
where a.key = b.key
and b.key = c.key
or perhaps c relates back directly to a so it is a.key = c.key where key can be any column whose value is equilivent in what it represents to the value it is being compared to, that is, student_number = student_number or the columns regardless of name are both building numbers, room numbers, etc ....
This is not your exact solution but it should help.
HTH -- Mark D Powell --