Why Does Using `mysqli_fetch_array()` Multiple Times Cause Issues With Result Sets?

Redundant mysqli_fetch_array() Calls: A Common Pitfall

Accessing the results of a database query more than once can be a challenging task. One common approach involves using mysqli_fetch_array(), a function that retrieves a row from the result set and advances the cursor to the next row. However, using the same result set multiple times with mysqli_fetch_array() can encounter limitations.

The sample code presented attempts to populate both a table row and column using data from a database, but it faces the issue of not being able to use the same result set twice with mysqli_fetch_array(). The reason for this is that each call to mysqli_fetch_array() advances the cursor to the next row.

To effectively bypass this limitation, it is recommended to decouple data manipulation from output. This means retrieving and storing the data into an array or data structure first and then utilizing it as needed:

<code class="php">// Select and store data into an array
$db_res = mysqli_query( $db_link, $sql );
$data   = array();
while ($row = mysqli_fetch_assoc($db_res)) {
    $data[] = $row;
}

// Use the stored data multiple times
// Top row
foreach ($data as $row) {</code>

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