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Checksum for a whole record
Message
De
08/03/2003 18:27:23
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00763322
Message ID:
00763360
Vues:
18
Alex,

See Message # 714561

MD5 fingerprints are really handy. I use it for many different things.

One use case is very similar to yours. We have an application that imports data from text files into SQL Server. The first thing we do is make sure that a given file hasn't been imported yet. We do this by comparing the MD5 fingerprint of the import file with the fingerprints of previously imported files that are saved in a SQL Server table. It's extremely fast and reliable. We then compute an MD5 fingerprint of each record (since the importfile doesn't contain a PK) and make sure that we haven't processed the record yet. This seems to be very similar to your requirement.

HTH
>Hi everybody,
>
>Wondering if anyone has a function to create a checksum for a WHOLE record in a table.
>
>For example, I have a table that has 128 fields and need a quick way to find duplicate records. I thought about doing a sys(2007) of a couple of fields, but not only I am getting unreliable results (several records that are different are yielding the same checksum) but I now need to compare ALL fields in order to determine uniqueness.
>
>If anyone can share some code or if there's anything already built into vfp, I'd appreciate a pointer...
>
>Thanks a lot!
>
>Alex
Daniel
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