Thread: GUID Unique identifer theory question

I ended up rewriting an old calendar app because of the duplicate key problem. I will leave the duplicate check code in thier just in case, it seems like the fastest solution. The amount of data depends on the client, I have some clients who enter large amounts of event, in those cases I push them to using sql server.

Better safe than sorry. I generally use a database, so the GUIDs I generate as primary keys gets checked by the database engine. But, yes, they do get checked and an Exception will be thrown if a duplicate is ever detected. If you are creating your own database, you should perform the check.

According to MSDN (Remarks) [ ^ ], GUIDs are as globally unique as possible. The probability of seeing two the same in the world (universe?) is very low. The probability of seeing two the same on a single PC is infinitesimal. Your process looks fine, if you hit a duplicate then just generate a new one and continue. Alternatively you may like to consider a simpler key, such as time and date, sequence number, combination of the two etc. It all...