检查特定行是否存在mysql

Question

I have a mysqli query which fetches all the images from the table(I have 5 images that I display). I am using a jquery slider to display them. 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. I don't want that happen so how do I only show the thumbnail if the image exists instead of showing empty thumbnail?

I tried the below but this doesn't work. I just need to see if image_one exists then show the thumbnail and the same for the rest of the images.

<?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>

Answer 1

we can not see your database design so look at your default value for

image_one and so on

The row count is allways 0 or 1 (because of 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.

depending on the default value test it

for example one of

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

put an if arround building 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 ?>