How to find the missing number.

[Chrysanthus]

Hello

I have a problem on how to resolve a missing number so i can reuse the number again
The thing is I want to use a number that is missing/removed from my table like this example

I have for example this numbers I a row.

1,2,3,4,5

if I where to remove the number 3 from that list sow I will have these values now

1,2,4,5

How can i find out what kind of number is missing sow I can find the number 3 that is missing so I can use it again.

If no number is missing I just want the script to add +1 on the last number I the table.

[drew010]

if you can get each number into an array element, then you can create a loop and check that $num[$i + 1] - $num[$i] is 1. if it is 2 or something greater, than there is a gap in the digits.

[Chrysanthus]

Originally posted by drew010
if you can get each number into an array element, then you can create a loop and check that $num[$i + 1] - $num[$i] is 1. if it is 2 or something greater, than there is a gap in the digits.

oki like this

$result = mysql_query("SELECT glycyID FROM gly_category WHERE glyorID='$_SESSION[regid]' ORDER BY ID"); 

$glycyID = array();

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

$glycyID[$row['glycyID']] = $row['glycyID'];

} 

but how do i go from here i?

[drew010]

im guessing the rows returned are the numbers alone.
so if you were to run
while($row = mysql_fetch_array($result)) {
echo $row['glycyID'] . "<br />\n";
}
you would see something like
1
2
3
4
5

if thats the case try this; starting from the loop

$numbers = array();
while($row = mysql_fetch_array($result)) {
  $numbers[] = $row['glycyID'];
}

$gap = FALSE;
for ($i = 0; $i < sizeof($numbers); ++$i) {
  if ($numbers[$i + 1] - $numbers[$i] > 1) {
    echo "Gap between " . $numbers[$i] . " and " . $numbers[$i + 1] . "<br />\n";
    $gap = TRUE;
    //do additional processing here
  }
}

if (!$gap) {
  //here you can add 1 to your db if needed
}

[/code]

[Chrysanthus]

Originally posted by drew010
im guessing the rows returned are the numbers alone.
so if you were to run
while($row = mysql_fetch_array($result)) {
echo $row['glycyID'] . "<br />\n";
}
you would see something like
1
2
3
4
5

if thats the case try this; starting from the loop

$numbers = array();
while($row = mysql_fetch_array($result)) {
  $numbers[] = $row['glycyID'];
}

$gap = FALSE;
for ($i = 0; $i < sizeof($numbers); ++$i) {
  if ($numbers[$i + 1] - $numbers[$i] > 1) {
    echo "Gap between " . $numbers[$i] . " and " . $numbers[$i + 1] . "<br />\n";
    $gap = TRUE;
    //do additional processing here
  }
}

if (!$gap) {
  //here you can add 1 to your db if needed
}

[/code] [/B]

Oki but how i get values

1
2

4
5

to printe/echo out missing value 3, if i would have these values how do i get to printe/echo out 6 insted?

1
2
3
4
5

time for me to sleep / brain needs sleep!

[Weedpacket]

If you know or you can reconstruct the original array (1,2,3,4,5), then you can use [man]array_diff[/man] to get an array of all the values that are missing from the new array.

$original_array = array(1,2,3,4,5);
$new_array = array(1,2,4,5);
print_r(array_diff($original_array, $new_array));
//output Array([0]=>3)

And of course if that array is empty, that's when you know to insert a 6.

[Chrysanthus]

Originally posted by Weedpacket
If you know or you can reconstruct the original array (1,2,3,4,5), then you can use [man]array_diff[/man] to get an array of all the values that are missing from the new array.

$original_array = array(1,2,3,4,5);
$new_array = array(1,2,4,5);
print_r(array_diff($original_array, $new_array));
//output Array([0]=>3)

And of course if that array is empty, that's when you know to insert a 6. [/B]

Something like this

$result = mysql_query("SELECT glycyID FROM gly_category WHERE glyorID='$_SESSION[regid]' ORDER BY glycyID DESC LIMIT 1 "); 
$row = mysql_fetch_array($result);

$original_array = array();
$new_array = array(); 

for ($i = 1; $i <= $row['glycyID']; $i++) {

  $original_array[$i] = $i;

}

$result = mysql_query("SELECT glycyID FROM gly_category WHERE glyorID='$_SESSION[regid]' ORDER BY glycyID"); 
while($row = mysql_fetch_array($result)) { 

$new_array[$row['glycyID']] = $row['glycyID']; 

}

print_r(array_diff($original_array, $new_array)); 

}

[Chrysanthus]

Originally posted by Chrysanthus
Something like this


How can i just get out value on $numbers; insted of just geting the text array

$result = mysql_query("SELECT glycyID FROM gly_category WHERE glyorID='$_SESSION[regid]' ORDER BY glycyID DESC LIMIT 1 "); 
$row = mysql_fetch_array($result);

$original_array = array();
$new_array = array(); 
$y = $row['glycyID'];
for ($i = 1; $i <= $row['glycyID']; $i++) {

  $original_array[$i] = $i;

}

$result = mysql_query("SELECT glycyID FROM gly_category WHERE glyorID='$_SESSION[regid]' ORDER BY glycyID"); 
while($row = mysql_fetch_array($result)) { 

$new_array[$row['glycyID']] = $row['glycyID']; 

}

if(!array_diff($original_array, $new_array)) {

$numbers = $y + 1;

}else{

$numbers = array_diff($original_array, $new_array); 
}

echo $numbers;
}