遍歷PHP一列中的所有行

Question

我有一個while循環從這句話在這裏

$stmt = $conn->prepare("SELECT images.*, users.profile_image, comments.* FROM 
images LEFT JOIN users ON images.user_id = users.user_id LEFT JOIN comments ON 
comments.user_id = users.user_id AND images.id = comments.image_id WHERE 
images.id = :id"); 

沒有問題的檢索信息，但我需要再次循環的意見，否則，第一循環，因爲註釋表中有兩行，所以再次循環。這會再次顯示所有內容，但包含評論的第2行。我怎樣才能讓它只循環評論。第一個循環只會檢索一個結果，因爲它始終是一個唯一的ID。

try { 
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 
    } catch (PDOException $e) { 
    echo 'Connection failed: ' . $e->getMessage(); 
    } 
$stmt->bindParam(':id', $id); 
$conn->beginTransaction(); 
$stmt->execute(); 
$conn->commit(); 

while ($row = $stmt->fetch()) 
{ 
$comment = $row['comment']; 
$title = $row['title']; 
$image = $row['image']; 
$username = $row['username']; 
$category = $row['category']; 
$description = $row['description']; 
$comments = array($row['comment']); 
} 
?> 
<h1><?php echo"$title"; ?></h1> 
    <img style="max-width: 100%; max-height:100%; margin-left: auto; margin- 
right: auto; display:block;" src="<?php echo "$image" ?>"/> 
     <?php 
      echo "<h2><span class='by'>By </span><a 
href='users.php/$username.html'>$username </a></h2>"; 
     echo "<h2><span class='by'>In the </span><a href='browse.php? 
category=space'>$category </a><span class='by'>category</span></h2>"; 
     echo "<h2><span class='by'>About this image:</span></h2> 
$description"; 
?> 
<?php 
    echo "<h2><span class='by'>Comments</span></h2> $comments"; 

?> 
<?php } 

else { 
if(!isset($row['id'])){ 
echo "empty"; 
} 
} 
?> 

謝謝！

更新

while ($crow = $cstmt->fetch()) 
    { 
     if($crow == false){ 
      echo "nothing here"; 
     } 
     else { 
     $comment = $crow['comment']; 
     echo "$comment"; ?><br /><br /><?php 
     } 
    } 

Answer 1

你可能會需要拆分此成一個單獨的查詢，或者使用一些邏輯，以確定是否是新的圖像或不

例如，如果拆分：

<?php 

$stmt = $conn->prepare("SELECT images.*, users.profile_image FROM 
images LEFT JOIN users ON images.user_id = users.user_id WHERE 
images.id = :id"); 


try { 
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 
    } catch (PDOException $e) { 
    echo 'Connection failed: ' . $e->getMessage(); 
    } 
$stmt->bindParam(':id', $id); 
$conn->beginTransaction(); 
$stmt->execute(); 
$conn->commit(); 

while ($row = $stmt->fetch()) 
{ 
$comment = $row['comment']; 
$title = $row['title']; 
$image = $row['image']; 
$username = $row['username']; 
$category = $row['category']; 
$description = $row['description']; 
// $comments = array($row['comment']); 
} 
?> 
<h1><?php echo"$title"; ?></h1> 
    <img style="max-width: 100%; max-height:100%; margin-left: auto; margin- 
right: auto; display:block;" src="<?php echo "$image" ?>"/> 
     <?php 
      echo "<h2><span class='by'>By </span><a 
href='users.php/$username.html'>$username </a></h2>"; 
     echo "<h2><span class='by'>In the </span><a href='browse.php? 
category=space'>$category </a><span class='by'>category</span></h2>"; 
     echo "<h2><span class='by'>About this image:</span></h2> 
$description"; 
?> 
<?php 

// THIS QUERY WON'T WORK , IT IS FOR CONCEPT ONLY 
     $CommentsStmt = $conn->prepare("SELECT comments.* FROM comments WHERE comments.user_id = :user_id AND comments.image_id = :image_id"); 
     $CommentsStmt->bindParam(':user_id', $row['user_id'] , ':user_id' , $row['image_id']); 
     $conn->beginTransaction(); 
     $CommentsStmt->execute(); 
     $CommentsStmt->commit(); 
     // add a check if it is blank 
     echo "<h2><span class='by'>Comments</span></h2> "; 
     while ($CommentsRow = $stmt->fetch()) 
     { 
      echo $CommentsRow['comment'],'<br /><br />'; 
     } 


?> 
<?php } 

else { 
if(!isset($row['id'])){ 
echo "empty"; 
} 
} 
?> 

用於非分裂版本

樣品

/************ 
**** 
******** only output the image details if this is a new image : 
**** 
************/ 
// NOT SURE WHERE TH IMAGE ID IS COMING FROM SO SUSTITUTE IT HERE: 
$current_image_id = $id; 
if($previousImageId !== $current_image_id){ 
?> 
      <h1><?php echo"$title"; ?></h1> 
      <img style="max-width: 100%; max-height:100%; margin-left: auto; margin- 
      right: auto; display:block;" src="<?php echo "$image" ?>"/> 
        <?php 
        echo "<h2><span class='by'>By </span><a 
      href='users.php/$username.html'>$username </a></h2>"; 
        echo "<h2><span class='by'>In the </span><a href='browse.php? 
      category=space'>$category </a><span class='by'>category</span></h2>"; 
        echo "<h2><span class='by'>About this image:</span></h2> 
      $description"; 
} 
/************ 
**** 
******** END --- only output the image details if this is a new image : 
**** 
************/