如何在MySQL表计算行数（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，其中包括$category1并在相同的代码$category2行的总数，我添加此代码之前它。

$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$totalrows echo 3 here。但是，大于3

Answer 1

他们有更多的行要覆盖$语句执行后使用使用fetchall（）

这样反而试试这个

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

Answer 2

尝试rowCount时（）的行

的计数

$totalrows = $stmt->rowCount(); 

Answer 3

试试这个

$stmt = $conn->prepare("SELECT SQL_CALC_FOUND_ROWS 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(); 
$conn->prepare('SELECT FOUND_ROWS() as COUNT'); 
$conn->execute(); 
$count = $conn->fetchColumn(); 
echo $count; //here's your total count