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Zach wrote:
"I do generally find that the more brief I am in
describing an issue, the
more likely I am to get a reply. Then details
can be given if needed, in
further correspondences."
I would like to disagree with this. I am only a newbie to php and
have found that if I can describe to my best ability the problem I'm
having I can get a reply that helps me in the best way in 1 or 2 replies.
There is none of this back and forward and end up still getting nowhere.
You have to wait for some replies, but they are worth it.
-------Original Message-------
Date: Thursday, 24
January 2002 1:02:07 p.
Subject: RE: [PHP-DB] #
of Records in Table
There are many columns of data in the table. The only
column that I would
like to extract a value from is the password field
(this is the key as
well). I do not have an AUTO_INCREMENT field.
Although, I see how adding
that field could be of use by using it with
the SELECT MAX() as you
mentioned.
The last record is whatever
the last record was inserted using INSERT INTO.
To give you the overall
picture of what I am trying to accomplish:
1) I am opening up a db
table and searching for the password of the last
record in the
table
2) I then open a flat file and search for that password and grab
the next
record after that (as records are appended to the end of the
flat file) and
any other subsequent records added to the flat
file
3) Write those new records to the db table
In this
scenario, the last record would be the last record from the flat
file
added to the db table.
Another suggestion from [EMAIL PROTECTED]
was to:
Select your password field, and whatever other fields you
need to
Use
-mysql_num_rows() to capture the number of rows
returned
-mysql_data_seek() to position pointer on last row (remember
indexing
starts at 0)
-mysql_fetch_row() or mysql_fetch_array(),
your choice, to return the
data.
This is done with one select
statement, however all the passwords from the
table have to be loaded
into array (perhaps not the most efficient way? But
better than what I
had come up with.).
I do generally find that the more brief I am in
describing an issue, the
more likely I am to get a reply. Then details
can be given if needed, in
further correspondences.
I will give
that AUTO_INCREMENT and SELECT MAX() a try as
well.
Zach
-----Original Message-----
From: DL Neil
[mailto:[EMAIL PROTECTED]]
Sent:
Wednesday, January 23, 2002 3:27 PM
To: Zach Curtis
Cc: [EMAIL PROTECTED]
Subject:
Re: [PHP-DB] # 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" <[EMAIL PROTECTED]>
To: "DL
Neil" <[EMAIL PROTECTED]>
Cc:
<[EMAIL PROTECTED]>
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:[EMAIL PROTECTED]]
>
Sent: Wednesday, January 23, 2002 2:08 PM
> To: Zach Curtis
>
Cc: [EMAIL PROTECTED]
>
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" <[EMAIL PROTECTED]>
> To:
"DL Neil" <[EMAIL PROTECTED]>
>
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:[EMAIL PROTECTED]]
>
> Sent: Wednesday, January 23, 2002 1:11 PM
> > To: Zach
Curtis; [EMAIL PROTECTED]
> >
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
> >
> >
> >
> >
>
>
>
>
>
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