[Gambas-user] Problem with Gambas and MySql

[Fernando Martins]

On 10/05/2013 01:25 AM, Willy Raets wrote:
> On Fri, 2013-10-04 at 22:53 +0200, Willy Raets wrote:
>
> Nando, Fernando and Caveat,
>
> Thanks for your responses.
>
>> Content in 'ICzakgewicht' can be like this:
>> | ID | Gewicht |
>> 345 100
>> 345 100
>> 345 50
>> 347 200
>> 347 200
>> 347 200
>> 347 200
> @ Fernando and Caveat
>
> Above you can see that more than one record can be exactly the same.
> At any time only one of them needs to be removed.
> With Gambas this can be done, looking for the first record meeting the
> criteria, delete it, next update and leave the table.
>
> With SQL DELETE all records that meet the criteria will be deleted
> instead of only one.
>
> That is why this is not an option.
>
>
"duplicate rows are and always were a mistake in SQL", C.J.Date

http://books.google.nl/books?id=y_eVBB5qdwMC&pg=PA159&lpg=PA159&dq=c+j+date+duplicate+records&source=bl&ots=DjN-LDuU2B&sig=5-vlJ8itEkC7h6aFMt2PxHkT-ug&hl=en&sa=X&ei=1cdPUtjSCcHH0QWvooGQCw&redir_esc=y#v=onepage&q=c%20j%20date%20duplicate%20records&f=false

In my experience, most often there is a design problem with the database 
allowing for duplicates. With duplicates, you step out of the set theory 
behind relational dbs and enter into trouble. I admit I have done it 
myself, but best be avoided.