Re: # of Records in Table

Zach, We're going back and forth on this and getting no where... So far all you have informed us is that the table has one column, which contains a bunch of passwords (I also suggest that this is not really the case and there'll at least be some sort of userId field - but you haven't bothered to tell me/us that) The concept of "last" in relational terminology is ambiguous. Do you mean last entered, or do you mean the row with the field containing the highest value in the column - for example. Some people are used to the idea that there is also some 'phantom' rowId that counts/labels each row. In other file systems this might have been the case, but the physically last record in an RDBMS table-file may not conform to either of the "last" definitions mentioned above. There is no such 'highest' in an RDBMS unless you put it there - as mentioned by another correspondent, it's a good idea to use some sort of 'id' field in every table. This can be generated for you with the AUTO_INCREMENT feature. With appropriate design, eg first record has id=1 and the succeeding records have id-s with ascending values, then you can use SELECT MAX() against the 'id' or possibly against the AUTO_INCREMENT feature. These commands are well documented - RTFM. Many tutorials with plenty of examples of authentication techniques exist on the PHP/MySQL web sites. Next time, please don't be so (repeatedly) parsimonious in the provision of information, if you expect/hope that someone is going to give their (free) time to help you out. (grumble) =dn ----- Original Message ----- From: "Zach Curtis" <zach@populus.com> To: "DL Neil" <PHPml@DandE.HomeChoice.co.uk> Cc: <php-db@lists.php.net> Sent: 23 January 2002 21:52 Subject: RE: [PHP-DB] # of Records in Table > The key field is the password field, which is also the field that I would > like to retrieve for that last record. > > > Zach > > -----Original Message----- > From: DL Neil [mailto:PHPml@DandE.HomeChoice.co.uk] > Sent: Wednesday, January 23, 2002 2:08 PM > To: Zach Curtis > Cc: php-db@lists.php.net > Subject: Re: [PHP-DB] # of Records in Table > > > Zach, > > How can this "last record" be identified? Is there a key field or something > similar? > > Again: We might need to see the table definition to answer this. > > Please advise, > =dn > > > ----- Original Message ----- > From: "Zach Curtis" <zach@populus.com> > To: "DL Neil" <PHPml@DandE.HomeChoice.co.uk> > Sent: 23 January 2002 20:49 > Subject: RE: [PHP-DB] # of Records in Table > > > > The last record should be whatever the last record is in the table. For > > example, if there are 1000 records in the table which COUNT(*) will tell > me, > > how can I get the password for record 1000. The only thing I can do that > > would probably work is two query statements, one selecting COUNT(*) and > the > > other selecting "password". What I don't like about this method is that I > > would have to retrieve all of the passwords into an array, which I would > > assume would be slow on larger tables. Ideally, I thought their would be a > > way to do this operation in one select statement. Any thoughts? > > > > > > Zach > > > > -----Original Message----- > > From: DL Neil [mailto:PHPml@DandE.HomeChoice.co.uk] > > Sent: Wednesday, January 23, 2002 1:11 PM > > To: Zach Curtis; php-db@lists.php.net > > Subject: Re: [PHP-DB] # of Records in Table > > > > > > Zach, > > > > > What syntax can I use to determine how many records are in a MySQL table > > and > > > then retrieve the value of the field "password" for the last record? I > > tried > > > using some combinations of COUNT(*) and LIMIT with no success. > > > > > > SELECT COUNT(*) will answer the first part. What did you try that lacked > > success? > > > > How do you define "last record"? We might need to see the table definition > > to answer this. > > > > Regards, > > =dn > > > > > > > > > > > > > > -- > PHP Database Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-db-unsubscribe@lists.php.net > For additional commands, e-mail: php-db-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net > >