Yes, they are very different.
The third query depends on a unary NOT operator and would require
rearranging the query to have it make sense.
The second query also uses a unary NOT operator, but a simple parser could
accommodate the problem and treat the "AND NOT" as a single operator.
Ralph
> -----Original Message-----
> From: Poul Henrik Jørgensen [mailto:[log in to unmask]]
> Sent: Monday, September 24, 2001 11:30 AM
> To: [log in to unmask]
> Subject: Re: CQL NOT Operator
>
>
> Hi Ray,
>
> If we are inventing a new query syntax intended to be
> accessible to the rest
> of the World (i.e. outside the Z39.50 Community), we should
> assume that they
> are familiar with standard Boolean logic - not the Z39.50 Type-1 Query
> syntax.
>
> Is there any difference between the results of the following
> three queries?
>
> 1) Bib1.Author="Ralph" ANDNOT Bib1.Title="The Dreamer"
> 2) Bib1.Author="Ralph" AND NOT Bib1.Title="The Dreamer"
> 3) NOT Bib1.Title="The Dreamer" AND Bib1.Author="Ralph"
>
> Best regards,
> Poul Henrik
> mailto:[log in to unmask]
>
>
>
>
>
>
>
> Best regards,
> Poul Henrik
> mailto:[log in to unmask]
>
>
>
>
> -----Original Message-----
> From: Ray Denenberg [mailto:[log in to unmask]]
> Sent: 24. september 2001 16:22
> To: [log in to unmask]
> Subject: Re: CQL NOT Operator
>
>
> Poul Henrik Jørgensen wrote:
>
> > If alternatively we wish to introduce a new boolean
> operator composed of
> the
> > well binary operator AND in some combination with the unary
> operator NOT,
> > then we should call it something else e.g. either AND-NOT
> or NOT-AND.
>
> We're not introducing a new boolean operator. It's the same
> "and-not" that
> we
> have in the type-1 query. (If you want to view it as some
> combination of
> unary
> NOT and binary AND, fine, but that doesn't change the fact
> that it's the
> same
> binary and-not we've always had in Z39.50.)
>
> --Ray
>
> --
> Ray Denenberg
> Library of Congress
> [log in to unmask]
> 202-707-5795
>
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