Question

问题1：是否可以将第一次while循环的输出结果作为第二次循环的变量进行查询？

我在下面有mySQL表“reorder_in_process”：

(`id`, `item`, `to_order`, `cat_no`, `supplier`) VALUES
(48, 'Petri Dish', 62, 1006, 'Progressive'),
(47, 'Beaker', 46, 1005, 'Progressive'),
(46, 'Tissue', 17, 1008, 'Needpoint'),
(45, 'Pipet', 77, 1004, 'Kumpulan');

我的php下面：

<?PHP
include ('db.php');
$sql4 = "SELECT DISTINCT supplier FROM reorder_in_process";
$result4 = mysqli_query($con,$sql4);
$supplier4 = $row4['supplier'];
$i=0;

while($row4 = mysqli_fetch_array($result4)){
echo "<h4>".$row4['supplier']."</h4>";

echo  "<div><table><tr>
                        <th>No</th>
                        <th>Item</th>
                        <th>Cat. No</th>                                            
                        <th>Buy QTY</th>
                        <th>Supplier</th>                   
                    </tr>";
$sql5 = "SELECT * FROM reorder_in_process WHERE supplier=$supplier4";
$result5 = mysqli_query($con,$sql5);
while($row5 = mysqli_fetch_array($result5)) {
$i++;
    echo "<tr>
            <td>".$i. "</td>
           <td>".$row5['item']."</td>
           <td>".$row5['cat_no']."</td>
           <td>".$row5['to_order']."</td>
           <td>".$row5['supplier']."</td>      
     </tr>";
}
echo "</table></div>";
}
mysqli_close($con);
?>

我不行......我想要输出结果如下：

Progressive
No  Item    Cat. No Buy QTY Supplier
1   Petri Dish  1006    62  Progressive
2   Beaker      1005    46  Progressive

Needpoint
No  Item    Cat. No Buy QTY Supplier
1   Tissue  1008    17  Needpoint

Kumpulan
No  Item    Cat. No Buy QTY Supplier
1   Pipet   1004    77  Kumpulan

请帮助找出我的错误和解决方案。感谢。

Answer 1

您不需要像这样运行两个查询。

不是执行一个查询，而只是在循环内再次查询相同的表，修改您的结构，这样您只需查询一次表。只需ORDER BY supplier并检查当前行供应商是否与上一行供应商不同。（披露：我还没有对这个逻辑进行全面测试，可能需要进行一些调整）。

$result = mysqli_query($con, "SELECT * FROM reorder_in_process ORDER BY supplier");
$first_iteration = true;
$current_supplier = null;

while($row = mysqli_fetch_assoc($result)){
    // If a new supplier is encountered, close the first table (if its no the first iteration) and add new header + start new table 
    if ($row['supplier'] != $current_supplier) {
        if ($first_iteration == false)
            echo "</table></div>";

        $i = 1;
        $first_iteration = false;
        $current_supplier = $row['supplier'];
        echo "<h4>".$row['supplier']."</h4>";
        echo  "<div><table><tr>
                    <th>No</th>
                    <th>Item</th>
                    <th>Cat. No</th>                                            
                    <th>Buy QTY</th>
                    <th>Supplier</th>                   
                </tr>";
    }

    echo "<tr>
                <td>".$i. "</td>
               <td>".$row['item']."</td>
               <td>".$row['cat_no']."</td>
               <td>".$row['to_order']."</td>
               <td>".$row['supplier']."</td>      
         </tr>";
    $i++;
}
echo "</table></div>";

Answer 2

首先，下面的行是未定义的，因为它在while循环之外

 $supplier4 = $row4['supplier'];

将上面的代码推入内部，while循环和字符串应该用这样的单引号括起来

 "...supplier='$supplier4'"

您需要为每个新供应商重置$i=1

更新1：

<?PHP
include ('db.php');
$sql4 = "SELECT DISTINCT supplier FROM reorder_in_process";
$result4 = mysqli_query($con,$sql4);

while($row4 = mysqli_fetch_array($result4)){

    $i=1;
    $supplier4 = $row4['supplier'];

    echo "<h4>".$row4['supplier']."</h4>";

    echo  "<div><table><tr>
                            <th>No</th>
                            <th>Item</th>
                            <th>Cat. No</th>                                            
                            <th>Buy QTY</th>
                            <th>Supplier</th>                   
                       </tr>";

    $sql5 = "SELECT * FROM reorder_in_process WHERE supplier='$supplier4'";
    $result5 = mysqli_query($con,$sql5);
    while($row5 = mysqli_fetch_array($result5)) {

        echo "<tr>
                <td>".$i. "</td>
               <td>".$row5['item']."</td>
               <td>".$row5['cat_no']."</td>
               <td>".$row5['to_order']."</td>
               <td>".$row5['supplier']."</td>      
         </tr>";

         $i++;
    }
    echo "</table></div>";
}
mysqli_close($con);
?>

PHP 1st while循环的输出结果为2nd而while循环的变量用于查询

2 个答案: