find duplicate addresses in database, stop users entering them early?

Question

How do I find duplicate addresses in a database, or better stop people already when filling in the form ? I guess the earlier the better?

Is there any good way of abstra

Answer 1

In my opinion, assuming that you already had a lot of dirty data in your DB,

You have to do build your "handmade" dirty filter which may detect a maximum of german abreviation ...

But If you treat a lot of data, you will take the risk to find some false-positive and true-negative sample...

Finally a semi automated job (machine with human assist when probability of a case of false-positive or true-negative is too high) will be the best solution.

More you treat "exception" (because human raise exception when filling data), more your "handmade" filter will fit your requierement.

In the other hand, you may also use a germany address verification service on user side, and store only the verified one...