Question

INSERT INTO Activity_Feed (userID,Type,DataIDs,PodID) 
VALUES ( 1437
      , 'eventattend'
      , (SELECT LEFT(EventID, LEN(eventID) - 1 as nvarchar) 
         FROM ( 
            SELECT EventiD + ', ' 
            FROM   events 
            FOR XML PATH ('')) c (EventID))
      , 5)

Basically I want to take a bunch of IDs from a table and insert them as a comma delimited string into a varchar field.

E.g.

Activity_Feed (table)

activityID   1
userID       2
DataIDs      1,3,4,56,367 // This would be the (Select Ids FROM bit)

I want to take a bunch of RSVP IDs from a table and stick their IDs in the field…

To further explain I wanted to avoid normalizing the query because of the nature of this query. Let me know if I should still separate out the data…

The activity feed works like this…

I create a new entry in activity with a type of event_attending (which is an event I am attending.

I timestamp it, I enter the ID for the event in the dataIDs field any new activity matching event_attending in a 6 hour period fires an update record rather than insert

I keep the timestamp the same but update the ID’s that are associated with that time period so basically update the IDs with the latest event attendance within that time period.

I thought normalizing seemed like overkill 😀 is there such thing as overkill with normalization?

Answer 1

Always normalize your database.

This is totally not wrong but very poor in database design.

Reasons why this is very poor:

• hard to join tables
• hard to find values

Why not create table like this,

Activity

• ActivityID
• ActivityName

Feed

• FeedID
• FeedName

Activity_Feed

• FeedID
• ActivityID

so Activity_Feed table will contain something like this

FeedID  ActivityID
=====================
1         1
1         2
1         3
2         1
2         3
3         2
3         1

and you can now join the tables,

SELECT  a.ActivityName, c.FeedName
FROM    Activity a
        INNER JOIN Activity_Feed b
            ON a.ActivityID = b.ActivityID
        INNER JOIN Feed c
            ON b.FeedID = c.FeedID
-- WHERE  a.ActivityName = 1             -- or something like this