multiple compare

Hi,

I need to check a set of links against a large database that I have
created. As the links get added I check one by one that they don't get
added twice. I was wondering if it is possible to pass the entire SET
of links to be checked all at once instead of one by one. I am hoping
this will make my application run fast.

Thanks

Carl

>I need to check a set of links against a large database that I have
>created. As the links get added I check one by one that they don't get
>added twice.

A unique index on that field will prevent entering the same link twice,
without needing to run a separate query to check first.

>I was wondering if it is possible to pass the entire SET
>of links to be checked all at once instead of one by one. I am hoping
>this will make my application run fast.

If you use INSERT with multiple records and get an error about a
duplicate record, you may not know which record is the duplicate.

Thanks Gordon,

I was wondering if a column could be made unique. I looked into
altering the column to unique that I am using but I have been having
problems. Could you give me a hint as to how I could do this or
should I just recreate the table with the column being unique.

Thanks,

Carl


On Mar 4, 6:40 pm, gordonb.n6...@burditt.org (Gordon Burditt) wrote:
> >I need to check a set of links against a large database that I have
> >created. As the links get added I check one by one that they don't get
> >added twice.
>
> A unique index on that field will prevent entering the same link twice,
> without needing to run a separate query to check first.
>
> >I was wondering if it is possible to pass the entire SET
> >of links to be checked all at once instead of one by one. I am hoping
> >this will make my application run fast.
>
> If you use INSERT with multiple records and get an error about a
> duplicate record, you may not know which record is the duplicate.

carlbernardi@gmail.com <carlbernardi@gmail.com> wrote:
> I was wondering if a column could be made unique. I looked into
> altering the column to unique that I am using but I have been having
> problems. Could you give me a hint as to how I could do this or
> should I just recreate the table with the column being unique.

ALTER TABLE tablename ADD UNIQUE (fieldname);

If there are already duplicates, you might want to remove them first.
--
Rik Wasmus