Setting up database structure - sql

Question

I am trying to figure out the best way to restructure my database as I didn't plan ahead and now I am a little stuck on this part :)
I have a Table called Campaigns and a Table called Data Types.
Each campaign is a unique record that holds about 10 fields of data.
The data types contains 3 fields - ID, Type, Description
When You create a campaign, you can select as many data types as you would like.
1, 2 or all 3 of them.
My concern / question is - How can I store what the user selected with the campaign record?
I need to be able to pull in the campaign details but also know which data types were selected.
How I originally had it set up was the data types were in 1 field, comma separated but learned is not ideal to do that.
What would be the best way to accomplish this? Storing the data as XML ?
UPDATE -
Here is an example of the query I was trying to get to work (its probably way off).
BEGIN
SET NOCOUNT ON;
BEGIN
SELECT *
FROM (SELECT A.[campaignID] as campaignID,
A.[campaignTitle],
A.[campaignDesc],
A.[campaignType],
A.[campaignStatus],
A.[duration],
A.[whoCreated],
B.[campaignID],
B.[dataType],
(SELECT *
FROM Tags_Campaign_Settings
WHERE campaignID = #campaignID) AS dataTypes
FROM Tags_Campaigns AS A
INNER JOIN
Tags_Campaign_Settings AS B
ON A.[campaignID] = B.[campaignID]
WHERE A.[campaignID] = #campaignID
) AS a
FOR XML PATH ('campaigns'), TYPE, ELEMENTS, ROOT ('root');
END
END

Answer 1

Create a join table called Campain_DataType with campaignId and dataTypeId. Make sure they're foreign key constrained to the respective tables. When you query for campaign data, you can either create a separate query to get the data type information based on the campaignId, or you can do a left outer join to fetch campaigns and their data types together.
If you want to collapse the 3 data types into the same row, then give the following a shot. It's definitely on the hacky side, and it'll only work with a fixed number of data types. If you add another data type, you'll have to update this query to support it.
SELECT
Campaign.ID,
Campaign.foo,
Campaign.bar,
dataType1.hasDataType1,
dataType2.hasDataType2,
dataType3.hasDataType3
FROM
Campaign
LEFT OUTER JOIN
( SELECT
1 as hasDataType1,
Campaign_DataType.campaignID
FROM
DataType
INNER JOIN Campaign_DataType ON Campaign_DataType.dataTypeId = DataType.id
WHERE
DataType.Type = 'Type1'
) dataType1 ON dataType1.campaignID = Campaign.ID
LEFT OUTER JOIN
( SELECT
1 as hasDataType2,
Campaign_DataType.campaignID
FROM
DataType
INNER JOIN Campaign_DataType ON Campaign_DataType.dataTypeId = DataType.id
WHERE
DataType.Type = 'Type2'
) dataType2 ON dataType2.campaignID = Campaign.ID
LEFT OUTER JOIN
( SELECT
1 as hasDataType3,
Campaign_DataType.campaignID
FROM
DataType
INNER JOIN Campaign_DataType ON Campaign_DataType.dataTypeId = DataType.id
WHERE
DataType.Type = 'Type3'
) dataType3 ON dataType3.campaignID = Campaign.ID
The record you receive for each Campaign will have three fields: hasDataType1, hasDataType2, hasDataType3. These columns will be 1 for yes, NULL for no.

Answer 2

Looks to me like what you want here is a crosstab query. Take a look at:
Sql Server 2008 Cross Tab Query