You haven't followed the rules for XML concatenation.  Try the following instead.

SELECT @cols = STUFF(( SELECT DISTINCT TOP

This is a variant on interval packing.  Here is what I came up with.  I think there is a better way to approach this, but I don't really have time...

Do you really want to insert changed rows?  Usually people want to update changed rows and insert new rows.  As for identifying which are new/changed, I like EXCEPT unless your...

You should never use a NULL value as an endpoint of an interval.  It becomes complicated very quickly when both the beginning and end of an interval can be null. ...

You haven't set up your procedure to take parameters, but you've tried to pass in parameters.  From your procedure, it looks like you want to change it so that it...

I think that my degree in Linguistics actually helped prepare me more for working with databases than my degree in Mathematics did, mostly because it helped me think in a...