I am wondering if it is possible to take the results of a query and return them as a CSV string instead of as a column of cells.

Basically, we have a table called Customers, and we have a table called CustomerTypeLines, and each Customer can have multiple CustomerTypeLines. When I run a query against it, I run into problems when I want to check multiple types, for instance:

    Select * 
      from Customers a 
Inner Join CustomerTypeLines b on a.CustomerID = b.CustomerID 
     where b.CustomerTypeID = 14 and b.CustomerTypeID = 66

...returns nothing because a customer can't have both on the same line, obviously.

In order to make it work, I had to add a field to Customers called CustomerTypes that looks like ,14,66,67, so I can do a Where a.CustomerTypes like '%,14,%' and a.CustomerTypes like '%,66,%' which returns 85 rows.

Of course this is a pain because I have to make my program rebuild this field for that Customer each time the CustomerTypeLines table is changed.

It would be nice if I could do a sub query in my where that would do the work for me, so instead of returning the results like:

14
66
67

it would return them like ,14,66,67,

Is this possible?