Normalization is one of the most important and basic database principle , why is it that important?
So if you are a sql developer and you come across a table in which there are comma separated values and those are to be used to join another table ; what would you do? Parse it one by one? Use in clause?
Well the first you can later you can’t,
So now you have to join the tables what can be done is either create a shadow table (one entry per row) that is the solution to it ; in an existing structure that is gonna cost you alot of effort but on the same time it would enhance the performance and make joins more easy ;if you don’t want to do that and whatever problem is at hand is one time request, i suggest you to create a temp table put all your records in there get your joins straight!