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检查特定行是否存在mysql

[英]check if specific row exists mysql

I have a mysqli query which fetches all the images from the table(I have 5 images that I display). 我有一个mysqli查询,可从表中获取所有图像(我有5个图像显示)。 I am using a jquery slider to display them. 我正在使用jquery滑块显示它们。 The problem is if there are no 5 images I see blank page like if the user uploads just two images then the rest three thumbnails will be empty and when you click on them it shows empty area. 问题是如果没有5张图像,我会看到空白页,例如,如果用户仅上传两张图像,则其余三个缩略图将是空白的,当您单击它们时,它将显示空白区域。 I don't want that happen so how do I only show the thumbnail if the image exists instead of showing empty thumbnail? 我不希望发生这种情况,那么如何仅在图像存在时显示缩略图而不显示空白缩略图?

I tried the below but this doesn't work. 我尝试了以下方法,但这不起作用。 I just need to see if image_one exists then show the thumbnail and the same for the rest of the images. 我只需要查看image_one是否存在,然后显示缩略图,其余图像也一样。

<?php
 $stmt = $mydb->prepare("SELECT * FROM table where title = ? AND id = ? limit 1 ");
$stmt->bind_param('ss', $title, $id);
$stmt->execute();
 $result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
$path = 'images/';
?>


<div id="slides">

<?php if($result->num_rows > 0){?><div class="slide"><a class="fancybox" href="<?php echo $path.$row['image_one']?>" data-fancybox-group="gallery"><img class="cloudzoom appsld" src="<?php echo $path.$row['image_one']?>"/></a></div><?php };?>
<?php if($result->num_rows > 0){?><div class="slide"><a class="fancybox" href="<?php echo $path.$row['image_two']?>" data-fancybox-group="gallery"><img class="cloudzoom appsld" src="<?php echo $path.$row['image_two']?>"/></a></div><?php };?>
<?php if($result->num_rows > 0){?> <div class="slide"><a class="fancybox" href="<?php echo $path.$row['image_three']?>" data-fancybox-group="gallery"><img class="cloudzoom appsld" src="<?php echo $path.$row['image_three']?>"/></a></div><?php };?>
<?php if($result->num_rows > 0){?><div class="slide"><a class="fancybox" href="<?php echo $path.$row['image_four']?>" data-fancybox-group="gallery"><img class="cloudzoom appsld" src="<?php echo $path.$row['image_four']?>"/></a></div><?php };?>
<?php if($result->num_rows > 0){?><div class="slide"><a class="fancybox" href="<?php echo $path.$row['image_five']?>" data-fancybox-group="gallery"><img class="cloudzoom appsld" src="<?php echo $path.$row['image_five']?>"/></a></div><?php };?>

</div>

<div id="slide_menu">

<ul id="slide"> <!-- This is the thumbnail area -->
    <li class="fbar">&nbsp;</li>
    <?php if($result->num_rows > 0){?><li class="menuItem"><a href=""><img src="<?php echo $path.$row['image_one']?>"  /></a></li><?php }; ?>
    <?php if($result->num_rows > 0){?><li class="menuItem"><a href=""><img src="<?php echo $path.$row['image_two']?>"  /></a></li><?php }; ?>
    <?php if($result->num_rows > 0){?><li class="menuItem"><a href=""><img src="<?php echo $path.$row['image_three']?>"  /></a></li><?php }; ?>
    <?php if($result->num_rows > 0){?><li class="menuItem"><a href=""><img src="<?php echo $path.$row['image_four']?>"  /></a></li><?php }; ?>
    <?php if($result->num_rows > 0){?><li class="menuItem"><a href=""><img src="<?php echo $path.$row['image_five']?>"  /></a></li><?php }; ?>
</ul>


</div>

we can not see your database design so look at your default value for 我们看不到您的数据库设计,因此请查看您的默认值

image_one and so on image_one

The row count is allways 0 or 1 (because of Limit 1 ) 行计数始终为01 (由于Limit 1
Important are the fields image_one to image_five These fields are always present, regardless of whether they are empty or with file names are filled. 重要的是image_oneimage_five字段这些字段始终存在,无论它们为空还是使用文件名填充。

depending on the default value test it 根据默认值测试一下

for example one of 例如以下之一

  • if ($row['image_one'] > '') { 如果($ row ['image_one']>''){
  • if ($row['image_one'] > null { 如果($ row ['image_one']> null {

put an if arround building html. 放一个if arround构建html。

<?php if($result->num_rows > 0){?>
 <?php if ($row['image_one'] > '') 
   {?>
     <li class="menuItem">
     <a href=""><img src="<?php echo $path.$row['image_one']?>" /></a>
     </li>
   <?php 
   }?>
    .... next 4 other tests
 <?php if ($row['image_two'] > '') 
    ....

<?php } // END__$result->num_rows > 0 ?>

try something like 尝试类似

   ...
    <ul id="slide"> <!-- This is the thumbnail area -->
        <li class="fbar">&nbsp;</li>
        <?php
        foreach ( $row as $element => $val){
          if(isset($val)) {
            print "<li class='menuItem'><a href=''><img src=".$path.$val."/></a></li>";
          }
        }
        ?>
    </ul>
...

and the same for the 1st ( <div id="slides"> ) block 与第一个( <div id="slides"> )块相同

Im not 100% sure for pdo but its not too far away 我不能100%确定pdo,但距离不太远

<?php
 $sql = "SELECT * FROM table where title = $title AND id = $id limit 1 ";
 $result = mysql_query($sql);
 while ($row = mysql_fetch_array($result)) {
?>

<div class="slide">
   <a class="fancybox" href="images/<?php echo $row['DB-IMAGE-PATH-HERE']; ?>" data-fancybox-group="gallery">
      <img class="cloudzoom appsld" src="images/<?php echo $row['DB-IMAGE-PATH-HERE']; ?>"/>
   </a>
</div>

<?php } // end while loop ?>
</div> <!-- end id="slides" -->

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