A Looping Question

[e1seix]

I have the following loop:

 

$go=mysql_query("SELECT * FROM admin WHERE sku>1000 AND sku<9999 ORDER BY sku")or
die(mysql_error());
$numrow1=mysql_num_rows($go);

while($row = mysql_fetch_array( $go )) {

print $row[sku]."<br />";

}

 

which of course allows me to see all the skus that are already in use in my database. However, to do it the other way around... how would I rejig that code to show me which skus (which is always a number between 1000 and 9999 AREN'T in use, instead of having to scan the list to find ones that are missing, if you see what I mean.

 

many thanks,

[discomatt]

$go=mysql_query("SELECT * FROM admin WHERE sku>1000 AND sku<9999 ORDER BY sku")or
die(mysql_error());
$numrow1=mysql_num_rows($go);

while($row = mysql_fetch_array( $go ))
    $exists[] = $row['sku'];

for ( $i = 1000; $i <= 9999; $i++ )
    if ( !in_array( $i, $exists ) )
        $notExists[] = $i;

print_r($notExists);

 

I wouldn't recommend calling this script often though, as there are a ton of loops. There may be a more efficient way of doing this

[GingerRobot]

Hmm, can't think of an easy way to do it all though mysql, but you could do this:

 

<?php
$sql = "SELECT sku FROM admin WHERE sku BETWEEEN 1000 and 9999";
$result = mysql_query($sql) or die(mysql_error());
$taken = array();
$possible = range(1000,9999);
while($row=mysql_fetch_row($result)){
   $taken[] = $row[0];
}
$unused = array_diff($range,$possible);
echo '<pre>'.print_r($unused,1).'</pre>';
?>

[e1seix]

First example worked, the second one didn't.

 

Many thanks,

[GingerRobot]

Yeah, mine should have been:

 

<?php
$sql = "SELECT sku FROM admin WHERE sku BETWEEEN 1000 and 9999";
$result = mysql_query($sql) or die(mysql_error());
$taken = array();
$possible = range(1000,9999);
while($row=mysql_fetch_row($result)){
    $taken[] = $row[0];
}
$unused = array_diff($possible,$taken);
echo '<pre>'.print_r($unused,1).'</pre>';
?>

[craygo]

run another loop from 1000 to 9999 and compare it

 

<?php
$go=mysql_query("SELECT * FROM admin WHERE sku>1000 AND sku<9999 ORDER BY sku")or
die(mysql_error());
$numrow1=mysql_num_rows($go);

while($row = mysql_fetch_array( $go )) {
$skus[] = $r['sku'];
print $row[sku]."<br />";
}
for($i=1000; $i<=9999; $i++){
  if(!in_array($i, $skus)){
  echo $i."<br />";
  }
}
?>

 

Ray

 

EDIT: late again!!

[e1seix]

Actually, as opposed to displaying the results in an array, is there a way of doing it for each result as a single variable so I can utilise them in turn.

 

Just a thought. It looks as though Craygo's answer would be appropriate, but the code itself doesn't perform correctly. It just lists every number between 1000 & 9999.

 

Hmm...

[discomatt]

An array is, in a sense, a variable containing many variables. I'm not sure what you want to do, but if you can do it with a variable, chances are you can do it with an array entry.

[craygo]

That is because I left the print of the shu in

 

<?php
$go=mysql_query("SELECT * FROM admin WHERE sku>1000 AND sku<9999 ORDER BY sku")or
die(mysql_error());
$numrow1=mysql_num_rows($go);

while($row = mysql_fetch_array( $go )) {
$skus[] = $r['sku'];
}
for($i=1000; $i<=9999; $i++){
  if(!in_array($i, $skus)){
  echo $i."<br />";
  }
}
?>

 

Ray