-Original Message-
From: Lefevre, Steven [mailto:[EMAIL PROTECTED]]
Hey folks-
'nother question.
I'm not an SQL expert, and I think I need a subselect, which
means I need a workaround on MySQL 3.23 or whatever version it is.
Here's the tables I have, with the relevant columns:
I think the problem is in your table structure. If you did this:
Students:
- Name
- StudentID
Classes:
- ClassID
- Name
StudentsClasses:
- StudentID (PK)
- ClassID (PK)
(You make them a combined key by doing PRIMARY KEY (StudentID,ClassID) in
your table def.)
When you add a student to a class
From: Lefevre, Steven [EMAIL PROTECTED]
...I think I need a subselect...
It's rare that a sub-select is actually ~needed~, but it does happen. You can almost
always get around it with a JOIN of some sort.
Final result should look like
Student | Class
--
Steve
Student | Class
--
Steve Lefevre | Math101
Stacy Adams | Intro to SQL
Something like
SELECT Student.Name, Classes.Name FROM Students, Classes WHERE
Students.StudentID = . $ID . AND Classes.Name IN ( SELECT
Classes.Name
FROM Classes WHERE ClassID = Students.ClassID )
Is this too simple?
select distinct p.symbol, i.name from portfolio p, stockinfo i
where p.symbol = i.symbol
and p.type = '401k'
and p.owner='jim'
order by p.symbol
-
Tom Haapanen -- Software Metrics/Equitrac Corp.
Advanced Printing Solutions -- http://www.metrics.com/
-Original
Hi Paul,
There is no direct way to make a string by concatinating strings of
different columns. But your problem can be solved in a different way.
select distinct p.symbol, i.name from portfolio p, portfolio pp, stockinfo i
where pp.type = '401k' AND pp.owner = 'jim'
and p.symbol = i.symbol
