How to Use MySQLi_Fetch_Array() Twice

How can I use mysqli_fetch_array() twice?

You don't need the while loop and you don't need to use mysqli_fetch_array() at all!

You can simply loop on the mysqli_result object itself many times. It implements Traversable interface that allows it to be used in foreach.

//Top row
foreach($db_res as $row) {
    echo "<td>". $row['Title'] . "</td>";
}

//leftmost column
foreach($db_res as $row) {
    echo "<tr>";
    echo "<td>". $row['Title'] . "</td>";
    .....
    echo "</tr>";
}

However, you should separate your DB logic from your display logic and to achieve this it is best to use fetch_all(MYSQLI_ASSOC) in your DB logic to retrieve all records into an array.

If you fetch all the data into an array, you can loop that array as many times as you want.

$data = $db_res->fetch_all(MYSQLI_ASSOC);

foreach($data as $row) {
    // logic here...
}

Use query twice mysql_fetch_array

$stuff = mysql_query("SELECT * FROM users");

while($s = mysql_fetch_array($stuff)){
# ....
}
// add this line
mysql_data_seek( $stuff, 0 );

while($r = mysql_fetch_array($stuff)){
# ...
}

Should do the trick

Another way is of course to store your result in an array and reuse that

Why does mysqli_fetch_array() return array double the size?

Because it also includes an array filled with columns's positions (i.e: 0, 1, 2, 3 and id, username, password, email). Both id and 0 hold the same data.

If you only want the string indexes, you can use mysqli_fetch_assoc (http://php.net/mysqli_fetch_assoc)

double results in my array ( mysql_fetch_array )

From the manual:

mysql_fetch_array — Fetch a result row as an associative array, a numeric array, or both

By default, mysql_fetch_array gives both associative and numeric indexes. You don't want this. You can limit it with the second parameter:

$query_result_array = mysql_fetch_array($query_result, MYSQL_NUM); // numeric keys only
$query_result_array = mysql_fetch_array($query_result, MYSQL_ASSOC); // associative keys only

You can also use mysql_fetch_row to only get numeric keys, or mysql_fetch_assoc to only get associative keys.

$query_result_array = mysql_fetch_row($query_result); // numeric keys only
$query_result_array = mysql_fetch_assoc($query_result); // associative keys only

mysqli_fetch_array() foreach loop duplicates

By default, mysqli_fetch_array() returns both an Associative Array ($key => $value) and a Numeric Array (0 => value), which is why you're getting duplicates - some of the entries have the column name as the key, the others have a numeric index.

If you want an associative array, you could use:

 mysqli_fetch_array($q, MYSQLI_ASSOC);
 //or
 mysqli_fetch_assoc($q);

Or for a numeric array:

 mysqli_fetch_array($q, MYSQLI_NUM);
 //or
 mysqli_fetch_row($q);

For more info: http://www.php.net/manual/en/mysqli-result.fetch-array.php

How to user fetch_assoc() twice in a single php file?

Replace

while($row = $categoryResult->fetch_assoc()) {

with

foreach($categoryResult as $row)

It does the same but the foreach approach uses an automatic iterator that will always start from the beginning of the result set.

$categoryResult = $mysqli->query();
// OR
$categoryResult = $stmt->get_result();

// from start to end as associative array
foreach($categoryResult as $row) {
    // ...
}

// again, from start to end as associative array
foreach($categoryResult as $row) {
    // ...
}

If for some reason, you must use while loop and the manual approach then you need to ensure that you always reset the internal pointer to the first records before starting your loop. However, manual looping is not recommended. It is easier to make more errors when doing this manually with while

$categoryResult->data_seek(0);
while($row = $categoryResult->fetch_assoc()) {
    // ...
}