php - 如何计算 MySQL 表中的行数 (PHP PDO)

Question

这是我的代码

$stmt = $conn->prepare("SELECT tmdb_movies.movie_title,tmdb_movies.tmdb_id, count (tmdb_id),GROUP_CONCAT(DISTINCT genres.genres_name) AS genres_name

FROM tmdb_movies

JOIN genres USING (tmdb_id)

GROUP BY tmdb_movies.movie_title,tmdb_movies.tmdb_id

HAVING find_in_set('$category1', genres_name) AND find_in_set('$category2', genres_name) 

LIMIT $limit OFFSET $start"); 


     // Then fire it up
     $stmt->execute();

 // Pick up the result as an array
 $result = $stmt->fetchAll();

因为我无法计算在同一代码中包含 $category1 和 $category2 的总行数，所以我在它之前添加了这段代码。

$sql = "SELECT count(tmdb_id),group_concat(genres.genres_name) AS genres_name

 FROM `tmdb_movies` 

JOIN genres USING (tmdb_id)
GROUP BY tmdb_movies.tmdb_id
HAVING find_in_set('$category1', genres_name) AND find_in_set('$category2', genres_name) "; 

$result = $conn->prepare($sql); 
$result->execute(); 
$totalrows = $result->rowCount();
echo $totalrows;

但是 $totalrows 在这里回显 3。但是他们的行数比 3 多很多。

Answer 1

你在使用 fetchAll() 执行后覆盖了 $stmt

所以试试这个

$stmt->execute();
 $totalrows = $stmt->rowCount(); 
 echo $totalrows;
 // Pick up the result as an array
 $result = $stmt->fetchAll();