How do I select the data from a single cell?

[charles_i]

Now that I have selecting the ID working (thanks sitepoint forums!) I have a new problem.

I want to determine whether the data in a single cell (the 2nd column in the last row) is either 'on' or 'off' - previously successfully set by me.

This is the code I have but the "mysql_result" line produces the following error:

Warning: mysql_result(): Unable to jump to row 20 on MySQL result index 5 in /var/www/vhosts/sawebdev.ca/httpdocs/salsa/test.php on line 30

When I echo $result I get "$result Resource id #5" - which I presume is "index 5" - what is that? The row count is correct (20) and the field I am trying to get the data from ('session') is the 2nd one. I don't understand why it's "unable" to jump to row 20 when there are, in fact 20 rows at this point.

Here's the code:


//get last row of table
$sql = "SELECT COUNT(*) FROM congress";
$rowsresult = mysql_query($sql);
list($numRows) = mysql_fetch_row($rowsresult);
echo '$numRows ' . $numRows . "<br>"; //the number of rows in your table

//select 'session' column data
$query = "SELECT session FROM congress";
$result = mysql_query($query) or die(mysql_error());
echo '$result ' . $result . "<br>";

//put data of last 'session' column into $session
//THIS IS CODE THAT PRODUCES THE ERROR
$session = mysql_result($result,$numRows) or die(mysql_error());

Thanks
Charles

[longneck]

why are you retrieving 20 rows, just to look at the last row?

also, there is no second column in the last row; your query only retrieves one column!

[charles_i]

I don't know why I'm retrieving 20 rows to look at the last row - that's the code I was given when I asked how do I find the last row.

'congress' is the name of the table and 'session' is the name of the column I'm trying to retrieve. I thought I could directly query that one column.

[glowdot]

Someone gave you that code? Never listen to them again

//get last row of table
$sql = "SELECT COUNT(*) FROM congress";
$result = mysql_query($sql);
$numRows = mysql_result($result,0);
echo 'Rows: ' . $numRows . "<br>"; //the number of rows in your table

//select 'session' column data
$query = "SELECT session FROM congress LIMIT ".($numRows-1).",1";
$result = mysql_query($query) or die(mysql_error());
$lastSession = mysql_result($result, 0);
echo 'lastSession: ' . $lastSession . "<br>"; 

[charles_i]

Thanks! I think that's working now (initial test did anyway). That "someone" posted it on this forum in my last question. Guess you can't trust all the code you get in forums

[longneck]

i'm still uncomfortable with that code. why do you want the "last" row in the table? and how do you define "last"?

[charles_i]

I'm continuing this post but posted my next problem as a new question:
http://www.sitepoint.com/forums/show...17#post3468917