Question

我正在使用内部联接来列出帖子及其类别和评论，像这样：

    if($stmt = $pdo->prepare("SELECT * FROM posts 
    INNER JOIN categories ON posts.cat_id = categories.cat_id
    INNER JOIN comments ON posts.post_id = comment_id 
    WHERE user_id = :sid")){
    $stmt->execute(array('sid'=>$sid));

然后执行while循环列出它们

while($row = $stmt->fetch(PDO::FETCH_ASSOC)){

并且usaqe是：

$row['category'];

我想让评论的总行属于帖子，并显示如下：关于帖子的总评论：$row['total_coments'];

有可能吗？

Answer 1

您可以这样做，假设comment_id是唯一的，

if($stmt = $pdo->prepare("SELECT posts.*,(select count(comment_id) from 
comments) 
as total_coments
FROM posts 
INNER JOIN categories ON posts.cat_id = categories.cat_id
INNER JOIN comments ON posts.post_id = comment_id 
WHERE user_id = :sid")){
$stmt->execute(array('sid'=>$sid));

如何（COUNT）获取总行属于使用内部连接php的帖子？

1 个答案: