Question

I have one table:

horse
    ->id
    ->course
    ->date

Another one:

course
    ->title
    ->trackstyle

And a third one

trackstyle
    ->id
    ->style

The style for the course can be multiple, so I thought I will create a field and save the value(s) delimited with a comma.

ie:

trackstyle
id:1
style:galloping

id:2
style:flat

course
title:ascot
trackstyle:1,2    (as it's galloping and flat)

title=beverley
trackstyle:1      (as it's just flat)

Now, I have trouble to build a request that will query all three tables …

Is it the correct way to build my database?
Or should I just add a new column in my course table, where I will put the trackstyle in ‘hard’:

course
title: ascot
trackstyle: galloping, flat

title: beverley
trackstyle: flat

Answer 1

No this is not a good way to build the Database. Instead you have to do something like following

course
    ->title

trackstyle
    ->id
    ->style

And one join table

 course_trackstyles
       ->course_id
       ->trackstyle_id

Your query will be something like following

SELECT c.title, GROUP_CONCAT(t.style) 
FROM course c JOIN course_trackstyles ct ON ct.course_id = c.id
              JOIN trackstyles t ON ct.trackstyle_id = t.id
GROUP BY c.title