Question

I’m writing an export function, where I need to export contacts to Excel, and I’ve run into a technical snag – or perhaps a gap in my SQL skills is closer to the truth. 😉

Here’s the scenario:
I’ve got a bunch of contacts in a database. Each contact can have many different roles, for example a contact can be both C# Developer and DBA, or DBA and IT-manager. These are split into three tables, like so:

-------------------   -------------------   -------------------
*     Contact     *   *   ContactRole   *   *      Role       *
-------------------   -------------------   -------------------
* ID              *   * ContactID       *   * ID              *
* Name            *   * RoleID          *   * Name            *
* Address         *   -------------------   -------------------
-------------------   

Not too hard to follow. There’s a set of contacts, and a set of roles. These are joined by the ContactRole table on the respective IDs.

When I export the contacts, I need to have a column in the export with all the roles comma separated, like C# Developer, DBA or DBA, IT-manager.
The export will be done from ASP.NET/C# codebehind, so I figured I could do this in code should it come to that, but I’ve got a feeling it’s possible to do in the SQL.

The data comes from SQL Server 2005.

Answer 1

Try this

declare @Roles nvarchar(max)

select @Roles = case when @Roles is null then '' else @Roles + ', ' end + Role.Name
from  Role
inner join ContactRole on Role.ID = ContactRole.RoleID
where ContactRole.ContactID = @ContactID

select @Roles 

update:

Above code covers functionality for a single contact. You can create a scalar function with parameter @ContactID and call the function from a

Select Name, dbo.GetContactRoles(ID) From Contact