PHP MySQL查询没有返回完整的所需结果集

Question

我在PHP变量中放置了以下mysql_query：

$equalDimensions_query = 
"SELECT 'allEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth = $maxImageWidth AND imgHeight = $maxImageHeight
UNION ALL
SELECT 'widthEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth = $maxImageWidth AND imgHeight != $maxImageHeight
UNION ALL
SELECT 'heightEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images  
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth != $maxImageWidth AND imgHeight = $maxImageHeight";

我使用以下PHP将结果放入一个关联数组中

$equalDimensions_data = mysql_query($equalDimensions_query) or die('MySql Error' . mysql_error());

while ($row = mysql_fetch_assoc($equalDimensions_data)) { 
    $cnt[$row['COL1']] = $row['imgCount']; 
}

假设返回一组三个数组，其中第一个为allEqual，第二个为widthEqual，第三个为heightEqual（顺序无关紧要） ）。

唉，由于某种原因 还没有<{1}}：

allEqual

当我使用Array ( [heightEqual] => 0 [widthEqual] => 0 ) 以原始的“三个数组”形式显示检索到的数据时，我得到的结果只有两个数组：

print_r

然而，如果我使用Array ( [COL1] => heightEqual [imgCount] => 0 ) Array ( [COL1] => widthEqual [imgCount] => 0 ) 而没有循环，如下所示：

print_r

我返回了之前缺少的$equalDimensions_data = mysql_query($equalDimensions_query) or die('MySql Error' . mysql_error()); $equalDimensions_array = mysql_fetch_assoc($equalDimensions_data); print("<pre>"); print_r($equalDimensions_array); print("</pre>"); 数组：

allEqual

我理解由于在最后一种情况下缺少Array ( [COL1] => allEqual [imgCount] => 2 ) 循环，我只返回一个结果;但是为什么呢，在while循环的情况下，while结果似乎被跳过了？这是我的代码的问题吗？我感谢您提供的任何帮助。我为这么长的问题道歉;我想确保尽可能多地提供信息。

---

您可以在此处下载我的数据库架构：https://files.me.com/stefanmelnychenko/453l4z

Answer 1

这是您复制的地方。您不会更改变量或任何内容以复制任何错误（如果有）。

我检查了你的原理，一切都很好，这是php脚本：

<?PHP

// Make a MySQL Connection
mysql_connect("localhost", "root", "") or die(mysql_error());

//select database   
mysql_select_db("new_arrivals_imgs") or die(mysql_error());


$imgId=1;
$maxImageHeight=1;
$maxImageWidth=1;

 $equalDimensions_query = 
"SELECT 'allEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth = $maxImageWidth AND imgHeight = $maxImageHeight
UNION ALL
SELECT 'widthEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth = $maxImageWidth AND imgHeight != $maxImageHeight
UNION ALL
SELECT 'heightEqual' AS COL1,COUNT(*) AS imgCount FROM (
    SELECT imgHeight, imgWidth, imgId AS primaryId FROM primary_images  
    UNION ALL 
    SELECT imgHeight, imgWidth, primaryId FROM secondary_images
) AS union_table
WHERE primaryId = $imgId AND imgWidth != $maxImageWidth AND imgHeight = $maxImageHeight";

$equalDimensions_data = mysql_query($equalDimensions_query)
 or die('MySql Error' . mysql_error());

while ($row = mysql_fetch_assoc($equalDimensions_data)) { 
    $cnt[$row['COL1']] = $row['imgCount']; 
}

print_r($cnt);

?>

这就是结果：