FreeTDS Development Group

["Thompson, Bill D (London)" <bill_d_thompson AT ml.com>]

Shaun,

that "return NO_MORE_ROWS" is going to leap right out of this entire
code segment, n'est-ce pas ?
..in which case you'll only call the dbcanquery() after dbnextrow() has
returned NO_MORE_ROWS
..at which point there's no point in calling dbcanquery()

did you mean to code a "break" instead of the "return NO_MORE_ROWS" ?

Also, your table has 2.4 million rows.
does that mean the query behind this dbresults loop is returning 2.4
million rows ?
if so, you should try and cut that number down at source, via your
query.
..unless you have a nice fat network :-)

Bill

-----Original Message-----
From: freetds-bounces AT lists.ibiblio.org
[mailto:freetds-bounces AT lists.ibiblio.org] On Behalf Of craigs
Sent: 10 March 2005 12:03
To: FreeTDS Development Group
Subject: Re: [freetds] dbnextrow() question


Right having problems with this, i want to exit query when i get what i 
want, theres over 2.4 millions records in my table so really need to get

this right, can someone advise me if the following code would work.

while ((return_code = dbresults(dbconn)) != NO_MORE_RESULTS)
{
             if (return_code == SUCCEED)
             {
                        /* Bind results to program variables. */
                        dbbind(dbconn, 1, NTBSTRINGBIND, 0, (BYTE *)& 
PlaceName);
                        dbbind(dbconn, 2, FLT8BIND, 0,
(BYTE*)&Longitude);
                        dbbind(dbconn, 3, FLT8BIND, 0,
(BYTE*)&Latitude);
                        dbbind(dbconn, 4, NTBSTRINGBIND, 0, (BYTE *)& 
Country);
                        dbbind(dbconn, 5, NTBSTRINGBIND, 0, (BYTE *)&
Town);
                        dbbind(dbconn, 6, INTBIND, (DBINT)0, (BYTE *)& 
SweepRadius);
           
                        /* Retrieve and print the result rows. */
                        while (dbnextrow(dbconn) != NO_MORE_ROWS)
                        {
                                    tempDist = LatLonDistance( prev_lat,

prev_lon, Latitude, Longitude );
               
                                    tempDist = tempDist * 1000; 
//convert kilometers to meters
               
                                    if ( tempDist <= SweepRadius )
                                    {
                                            /* Find what i'm looking for

so i call a function to Insert into a table using variables above. */
                                            InsertRecord(roadsquery);
                  
                                            return NO_MORE_ROWS;
                                    }
                        }
                        dbcanquery(dbconn);
             }
}

Any help would be much appreciated, thanks.

Shaun.

craigs wrote:

> can i do the following using dbcanquery()
>
> while (dbnextrow(dbconn) != NO_MORE_ROWS)
> {
>     bind results to varialbes
>
>          if ( find what i want )
>          {
>               do something here
>                now exit doing the following
>
>             dbcanquery(dbconn);
>          }
> }
>
> will this let me exit the loop correctly with the variables still set?
>
>
>
> Thompson, Bill D (London) wrote:
>
>> Easy, cowboy.
>>
>> well, *might* is right , if you'll excuse the pun - as there is one
>> circumstance when it wouldn't go wrong.
>>
>> On the other hand, I *might* not have had the time to go into all the
>> gory details :-)
>>
>> Yours non-specifically,
>>
>> Bill
>>
>> -----Original Message-----
>> From: freetds-bounces AT lists.ibiblio.org
>> [mailto:freetds-bounces AT lists.ibiblio.org] On Behalf Of Lowden, James
K
>> Sent: 08 March 2005 17:57
>> To: ml AT freetds.org
>> Subject: RE: [freetds] dbnextrow() question
>>
>>
>>  
>>
>>> From: Thompson, Bill D (London)
>>> Sent: Tuesday, March 08, 2005 6:01 AM
>>>
>>> your next call to dblibrary *might* fail with a "results pending"
type
>>> error though, if you tray and do another operation on the same
channel
>>>   
>>
>>
>> What "might"?  *Will* fail, period. 
>> The code below doesn't tell the server to stop sending rows, and
doesn't
>> tell the library the that the result set was exhausted/cancelled.
>> db-lib maintains information about the state of the connection, and
will
>> refuse to send another query.  Anything else is a bug. 
>> The only exception would be if the last row fetched happened also to
be
>> the last row sent, i.e., the last row of the result set.  Some
>> implementations of db-lib (not FreeTDS, afaik), will note the
>> end-of-rowset packet and update the internal connection status
>> automatically.  Others will not do so until dbnextrow returns
>> NO_MORE_ROWS. 
>> Am I missing something? 
>> --jkl
>>
>>
>>  
>>
>>> -----Original Message-----
>>> From: freetds-bounces AT lists.ibiblio.org
>>> [mailto:freetds-bounces AT lists.ibiblio.org] On Behalf Of craigs
>>> Sent: 08 March 2005 10:58
>>> To: FreeTDS Development Group
>>> Subject: Re: [freetds] dbnextrow() question
>>>
>>>
>>> found an easier way of doin it.
>>>
>>> while (dbnextrow(dbconn) != NO_MORE_ROWS)
>>> {
>>>      if ( find what i want )
>>>      {
>>>            do something here
>>>            now exit doing the following
>>>
>>>         return NO_MORE_ROWS; // this will let you exit
>>>      }
>>> }
>>>
>>>
>>> Thompson, Bill D (London) wrote:
>>>
>>>   
>>>
>>>> Shaun
>>>>
>>>> see dbcanquery() or dbcancel() . dbcanquery looks like exactly what
>>>>     
>>>
>> you
>>  
>>
>>>> want.
>>>>
>>>> -----Original Message-----
>>>> From: freetds-bounces AT lists.ibiblio.org
>>>> [mailto:freetds-bounces AT lists.ibiblio.org] On Behalf Of craigs
>>>> Sent: 04 March 2005 12:19
>>>> To: FreeTDS Development Group
>>>> Subject: [freetds] dbnextrow() question
>>>>
>>>>
>>>> Could someone tell me how to exit this loop?  I dont want to run
>>>>     
>>>
>>> through
>>>   
>>>
>>>> thousands of unnecessary records when i find the one i want.
>>>>
>>>> while (dbnextrow(dbconn) != NO_MORE_ROWS)
>>>> {
>>>>     if ( find what i want )
>>>>     {
>>>>           do something here
>>>>           now i want to exit out off this loop
>>>>     }
>>>> }
>>>>
>>>> Shaun
>>>>     
>>>
>>
>> -----------------------------------------
>> The information contained in this transmission may contain privileged
>> and confidential information and is intended only for the use of the
>> person(s) named above. If you are not the intended recipient, or an
>> employee or agent responsible for delivering this message to the
>> intended recipient, any review, dissemination, distribution or
>> duplication of this communication is strictly prohibited. If you are
not
>> the intended recipient, please contact the sender immediately by
reply
>> e-mail and destroy all copies of the original message. Please note
that
>> we do not accept account orders and/or instructions by e-mail, and
>> therefore will not be responsible for carrying out such orders and/or
>> instructions.
>> If you, as the intended recipient of this message, the purpose of
which
>> is to inform and update our clients, prospects and consultants of
>> developments relating to our services and products, would not like to
>> receive further e-mail correspondence from the sender, please "reply"
to
>> the sender indicating your wishes.  In the U.S.: 1345 Avenue of the
>> Americas, New York, NY 10105.
>>
>>
>> _______________________________________________
>> FreeTDS mailing list
>> FreeTDS AT lists.ibiblio.org
>> http://lists.ibiblio.org/mailman/listinfo/freetds 
>> --------------------------------------------------------
>>
>> If you are not an intended recipient of this e-mail, please notify 
>> the sender, delete it and do not read, act upon, print, disclose, 
>> copy, retain or redistribute it. Click here for important additional 
>> terms relating to this e-mail.     http://www.ml.com/email_terms/ 
>> --------------------------------------------------------
>>
>> _______________________________________________
>> FreeTDS mailing list
>> FreeTDS AT lists.ibiblio.org
>> http://lists.ibiblio.org/mailman/listinfo/freetds
>>
>>  
>>
>
> _______________________________________________
> FreeTDS mailing list
> FreeTDS AT lists.ibiblio.org
> http://lists.ibiblio.org/mailman/listinfo/freetds


_______________________________________________
FreeTDS mailing list
FreeTDS AT lists.ibiblio.org
http://lists.ibiblio.org/mailman/listinfo/freetds 
--------------------------------------------------------
 
If you are not an intended recipient of this e-mail, please notify the 
sender, delete it and do not read, act upon, print, disclose, copy, retain or 
redistribute it. Click here for important additional terms relating to this 
e-mail.     http://www.ml.com/email_terms/ 
--------------------------------------------------------