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Re: XML and LDAP: Common APIs?

• From: mark hu <mark@f...>
• To: "John F. Schlesinger" <johns@s...>,'Rob Weltman' <rweltman@n...>, xml-dev@l...
• Date: Mon, 28 Aug 2000 10:03:20 -0400

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----- Original Message -----
From: John F. Schlesinger <johns@s...>
To: 'Rob Weltman' <rweltman@n...>; <xml-dev@l...>
Sent: Monday, August 28, 2000 12:20 AM
Subject: RE: XML and LDAP: Common APIs?


> What we did in EDA/SQL (if I remember right) was to ask the programmer to
> specify if the query was using 'string' or 'binary' format.
>
> If I specify 'employeeNumber > 200' using string format, then my 200 is
cast
> into the datatype of the database. If I am using 'binary' format (which
> almost nobody did) then I have to know the datatype (declared in the local
> metadata for the database).
>
> The advantage of the string method is that you can ask for an arbitrary
> query of the user and send it to the database as a string. The return data
> is self describing (as all SQL answer sets are) so that the table can be
> formatted for the user.
>
> In any case, I don't think you need to know the datatype to form the
query -
> though you may need it to understand the response! The SQL functions SUM
and
> AVERAGE do imply that the fields are in some way numerical.
>
> Yours,
> John F Schlesinger
> SysCore Solutions
> 212 619 5200 x 219
> 917 886 5895 Mobile
>
> -----Original Message-----
> From: Rob Weltman [mailto:rweltman@n...]
> Sent: Sunday, August 27, 2000 8:55 PM
> To: xml-dev@l...
> Subject: Re: XML and LDAP: Common APIs?
>
>
> "John F. Schlesinger" wrote:
>
> > Well, the problem isn't whether the query engine needs to know the data
> > type, it is whether I need to know the data type to formulate the
query -
> or
> > maybe I'm barking up the wrong tree?
> >
>
>   Suppose you want to search for employees with an employee number higher
> than
> 200. You could express that in LDAP filter syntax as "(employeeNumber >
> 200)".
> Should the query return a record for the employee with number 1000? It
> depends
> on if the value is considered a string or an integer (in LDAP it is
> determined
> by the syntax of the attribute).
>
> Rob
>
>
> >
> > Yours,
> > John F Schlesinger
> > SysCore Solutions
> > 212 619 5200 x 219
> > 917 886 5895 Mobile
> >
> > -----Original Message-----
> > From: rsanford [mailto:rsanford@n...]
> > Sent: Friday, August 25, 2000 3:48 PM
> > To: xml-dev@l...
> > Subject: RE: XML and LDAP: Common APIs?
> >
> > for single values the query engine wouldn't need to
> > know what the data type was but what about range
> > queries. for example, how would you search for
> > records where a date is between 2 march 98 and 4
> > august 99?
> >
> > rjsjr
> >
> > > -----Original Message-----
> > > From: John F. Schlesinger [mailto:johns@s...]
> > > Sent: Friday, August 25, 2000 11:25 AM
> > > To: 'KenNorth'; xml-dev@l...
> > > Subject: RE: XML and LDAP: Common APIs?
> > >
> > >
> > > Ken wrote:
> > > "How do you know whether a query should match a binary '101' or a
> decimal
> > > '101' if you don't use data types?"
> > >
> > > I don't think I need to know that to formulate a query. The
> > > system that does
> > > the matching will have to cast both the things being matched and my
> match
> > > string to some common form, but that's a different problem. In many
> cases
> > > everything is cast to a string - then my "101" matches ether a
> > > decimal "101"
> > > or a binary "101". If I meant a decimal "101" and it matched to a
binary
> > > "101" by mistake, then I was querying the wrong field.
> > >
> > > Yours,
> > > John F Schlesinger
> > > SysCore Solutions
> > > 212 619 5200 x 219
> > > 917 886 5895 Mobile
> > >
> > > -----Original Message-----
> > > From: KenNorth [mailto:KenNorth@e...]
> > > Sent: Thursday, August 24, 2000 4:37 PM
> > > To: xml-dev@l...
> > > Subject: Re: XML and LDAP: Common APIs?
> > >
> > >
> > >
> > >
> > > > Francis wrote:
> > > > "...Xpath (unlike XML-Schema)doesn't understand basic types like
> dates"
> > > >
> > > > I don't need data types to query.
> > >
> > > Okay, let's say you have a value of '101'.
> > >
> > > How do you know whether a query should match a binary '101' or a
decimal
> > > '101' if you don't use data types?
> > >
> > >
> > >
> > >
> > >
> > >
>
>
>
>
>

• References:
  • RE: XML and LDAP: Common APIs?
    • From: johns@s... (John F. Schlesinger)

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