Group Query Results in PHP

Question

I am using the following query to populate a table:

$result = mysql_query(\"SELECT vendor, part_number, machine, Sum(q_received) AS received, Sum(q_rejected) AS          


        

Answer 1

During each loop you have to decide if it is time to draw the heading--you're going to list a new vendor. If it isn't a new vendor, you're still listing parts for the one you drew the last heading for, so you don't want the heading or to end the table.

$current_vendor = false;
while($row = mysql_fetch_array($result)) {
    // listing a new vendor? Output the heading, start the table
    if ($row['vendor'] != $current_vendor) {
            if ($current_vendor !== false)
                echo '</table>[/fancy_table]'; // if we're changing vendors, close the table
        echo '
            <h4>'.$row['vendor'].'</h4>[fancy_table]
            <table>
                <tr>
                <th>Part Number</th>
                <th>Quantity Received</th>
                <th>Quantity Rejected</th>
                <th>Machine</th>
                </tr>
        ';
        $current_vendor = $row['vendor'];
    }
    // output the row of data
    echo '<tr>
        <td>'.$row['part_number'].'</td>
        <td>'.$row['received'].'</td>
        <td>'.$row['rejected'].'</td>
        <td>'.$row['machine'].'</td>
        </tr>
    ';
}
echo '</table>[/fancy_table]'; // close the final table

On another note, you should start updating this code to use PDO. Obviously, you're in the middle of updating something that used to exist... make PDO a part of this update. The mysql_* functions are on the way to deprecation, and soon they'll be gone.

PDO is not hard to transition into, and it is MUCH easier now while you're already working on things than it will be later, when you're faced with the "it isn't broke, don't fix it" problem.

Here's a quick look at your code using the superior PDO DBA method:

   $pdo = new PDO("mysql:host=localhost;dbname=database", '-username-', '-password-');
   $sql = '
        SELECT
            vendor, 
            part_number, 
            machine, 
            SUM(q_received) AS "received",
            SUM(q_rejected) AS "rejected" 
        FROM 
            qa_parts 
        GROUP BY 
            vendor, 
            part_number, 
            machine 
        ORDER BY 
            vendor ASC
    ';
    $statement = $pdo->prepare($sql);
    $statement->execute();
    while ($order = $statement->fetch()) {
        /* Put your table code here! */
    }

Documentation

• foreach - http://php.net/manual/en/control-structures.foreach.php
• mysql_query (DEPRECATED) - http://php.net/manual/en/function.mysql-query.php
• PDO - http://www.php.net/manual/en/book.pdo.php
• PDO::prepare - http://www.php.net/manual/en/pdo.prepare.php
• PDOStatement::fetch - http://www.php.net/manual/en/pdostatement.fetch.php
• PDOStatement::execute - http://www.php.net/manual/en/pdostatement.execute.php

Answer 2

You need to split your loop into two parts. First part checks if you've got a new/different vendor, and sets up the "outer" setup. Then the inner part which dumps out that vendor's parts.

e.g.

$prev_vendor = null;
while($row = ...) {
    if ($row['vendor'] != $prev_vendor) {
       ... new vendor stuff ...
       $prev_vendor = $row['vendor']; // update vendor for next iteration
    }
    ... dump this row's machine data ...
}