我使用以下代码对库存进行分组和求和。对于我的一些库存，如果发货量多于库存，我可能会得到负面结果，但我希望这些负数量项目不要显示在我拥有的"库存页面"中。有没有办法删除数量等于或小于 0 的行？
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ProductID | Color | Timestamp | Quantity | RowID |
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25 | Red | 10/10/10 06:22:15 | -250 | 1 |
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32 | Green | 10/10/10 06:23:45 | 100 | 2 |
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$query = "SELECT productid, color, SUM(Quantity) AS TotalQuantity FROM inventory GROUP BY productid, color";
$result = mysql_query($query) or die(mysql_error());
// Table markup here
echo '<tr><td>'. $row['productid'] . '</td><td>' . $row['color']. '</td><td>'. $row['TotalQuantity'];
// Table markup here
$query = "Select * from
(SELECT productid, color,
SUM(Quantity) AS TotalQuantity FROM inventory
GROUP BY productid, color) AS alias
where TotalQuantity > 0";