php - JOIN 同一个表中的同一列 - MYSQL

Question

我有这个表:

表 addonlist_final

TABLE 插件

首先，我必须JOIN 相同的addon_id，这样我才能获得所有需要的详细信息(我已经完成了)。然后我想JOIN表中具有相同标识(addon_id)的列，然后将数量相加。

到目前为止我有这段代码:

    <?php

include("conn.php");

echo "<table border='1' >";
echo "<tr>";
    echo "<th>Description</th>";
    echo "<th>Price</th>";
    echo "<th>Qty</th>";
    echo "<th>Total Cost</th>";
echo "</tr>";
$totaldue = 0;
$currentaddons = mysql_query("SELECT a.*, af.*
                            FROM addons AS a, addonlist_final AS af
                            WHERE a.addon_id = af.faddon_id and af.ftransac_id='2685'
                            ORDER BY af.timef DESC
                            ");

while($rows = mysql_fetch_assoc($currentaddons)){
    $desc = $rows['description'];
    $price = $rows['price'];
    $qty = $rows['quantity'];
    $totalcost = $price * $qty;
    $totaldue += $price * $qty;
        echo "<tr>";
            echo "<td>$desc</td>";
            echo "<td>$price</td>";
            echo "<td>$qty</td>";
            echo "<td>$totalcost</td>";
        echo "</tr>";
}

echo "</table>";

echo "<h3>Total Due: ".number_format($totaldue)."</h3>";

?>

这向我展示了这一点:

我要展示的是:

仅通过一个查询就可以做到这一点吗？提前致谢:)

Answer 1

你必须使用group by

SELECT a.description, sum(af.quantity) as quantity,price
FROM addons AS a, addonlist_final AS af
WHERE a.addon_id = af.faddon_id and af.ftransac_id='2685'
group by a.description
ORDER BY af.timef DESC