PHP，類別，從INNERJOIN選擇在哪裏

Question

嗨即時嘗試讓這個特定的代碼工作的類別頁面。不知道如何安排它。

 $cat = $_GET['cat']; 
} 
$record_count = $db->query("SELECT * FROM posts WHERE category_id='$cat'"); 
$per_page = 3; 
$pages = ceil($record_count->num_rows/$per_page); 

echo $cat; 

if (isset($_GET['p']) && is_numeric($_GET['p'])){ 
    $page = $_GET['p']; 
}else{ 
    $page = 1; 
} 
if($page<=0) 
    $start=0; 
    else 
    $start = $page * $per_page - $per_page; 
$prev = $page - 1; 
$next = $page + 1; 
$query = $db->prepare("SELECT post_id, title, date, image, LEFT(body, 150) AS body, category FROM posts WHERE posts.category_id=$cat INNER JOIN categories ON categories.category_id=posts.category_id order by post_id desc limit $start, $per_page"); 
$query->execute(); 
$query->bind_result($post_id, $title, $date, $image, $body, $category); 

這包括pagnation，特別是看這條線。但以分離需要的是似乎越硬CATEGORY_ID（至少對我來說）使用兩個MySQL表

帖比預期

$query = $db->prepare("SELECT post_id, title, date, image, LEFT(body, 150) AS body, category FROM posts WHERE posts.category_id=$cat INNER JOIN categories ON categories.category_id=posts.category_id order by post_id desc limit $start, $per_page"); 

：POST_ID標題日期圖像身體鏈路鏈接名稱CATEGORY_ID

類別：類別CATEGORY_ID

Answer 1

您的查詢片斷不按順序（特別是，哪裏去的地方），而且您沒有正確地執行準備好的語句。請注意，您在每個變量的位置放置一個問號，然後使用bind_param按順序填充問號。第一部分，"iii"，意味着有三個整數。

$query = $db->prepare("SELECT post_id, title, date, image, LEFT(body, 150) AS body, category 
    FROM posts 
    INNER JOIN categories ON categories.category_id=posts.category_id 
    WHERE posts.category_id=? 
    order by post_id desc 
    limit ?, ?"); 
$query->bind_param("iii", $cat, $start, $per_page); 
$query->execute();