How do I compare array value to the next value in array - php

Question

I am wanting to compare the next value in the array with my current value. If you look at my code I think you will see what I am trying to do but to explain I need only one picture to show if $row[2] is the same on the next loop thru.
My error start at // ERROR HERE in if Statement in the code below.
I am sure there is a simple solution to this but I don't know the proper name and could not find it in my searches.
-Disclaimer I am still an newbie at this please forgive me.
$connection = mysqli_connect($host, $user, $pass, $db);
if (mysqli_connect_errno($connection)) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
// create query
$query = "SELECT * FROM 1098";
$result = mysqli_query($connection, $query);
if (mysqli_num_rows($result) > 0) {
while($row = mysqli_fetch_row($result)) {
echo "<center>";
// ERROR HERE in if Statement
$nextrow = 1 + $row;
if ( $row[2] <> $nextrow[2]){
if ( $row[6] == "kit"){
$img ='<img style="width: 700px; height: 800px;" alt="Picture Not Found" src=" ';
$file = substr($row[2], -3);
$filepath='files/'.$row[6].'/'.$file.'_files/image001.png">';
echo $img.$filepath;
}
else
{
$img ='<img style="width: 700px; height: 280px;" alt="Picture Not Found" src=" ';
$filepath='files/'.$row[6].'/'.$row[2].'_files/image001.png">';
echo $img.$filepath ;
}
}
echo "</center>";
}
}

Answer 1

$nextrow = 1 + $row doesn't make sense. That would be attempting to add an integer to a database record, i.e. 1 + array('foo', 'bar', 'baz').
If you simply want to compare the current record with the previous record (on all loops after the first one) how about something like this:
while($row = mysqli_fetch_row($result)) {
print '<center>';
// If there is no previous record set (first record) or if the 2nd value is different.
if (!isset($prev_record) || $prev_record[2] != $row[2]) {
// ...
}
print '</center>';
// Assign the current row to a variable so that it's available on the next run.
$prev_record = $row;
}
Edit – here's an example of how you can get all records into a single array and then play with them:
$records = array();
while($row = mysqli_fetch_row($result)) {
$records[] = $row;
}
foreach ($records as $i => $record) {
$record; // current record
$records[$i-1]; // last record
$records[$i+1]; // next record
}
I would recommend splitting your data up into multiple tables, though, and using a cleaner approach.

Answer 2

$nextrow = 1 + $row;
Given $row is a row, this is not doing what you think it is.
If you want the nextrow from the query you have to fetch it.
If you can reverse your logic to use previous row , you could preserve that and compare it to the current row.
You could read them all into an array first, but on a big result set that would be expensive....
You could do two fetches, one to current row, one to next row,
And then add a lot of logic to deal with the first and last, and making current = next and fetching the next next :(
Or you could rework the query so it returned the data you need in one row.
You definitely can't do what you are trying to do though. There is no next row until you fetch. $row is an array of columns, there is no rows as in an array of rows.