Mysqli 查询只返回一行(最后一行)

Question

我正在尝试从我的数据库表中获取所有注释投票，该表属于$comments变量(在comment_votes表中称为item_id(中的注释，并且> 0。但是，在运行下面的脚本时，我只得到投票行之一(最后一个(。根据下面的数据库表值，我认为我应该有 4。IN(( 只返回一行还是我做错了其他事情？

$comments = "1,3,4,5,6,7,11,12,13";
$db_conn = new Database;
$stmt = $db_conn->connect->prepare("SELECT ID FROM `COMMENT_VOTES` WHERE VOTE > 0 AND `ITEM_ID` IN (?)");
$stmt->bind_param("s", $comments);
$stmt->execute();
$result = $stmt->get_result();
$votes = [];
while ($row = $result->fetch_assoc()) { 
    array_push($votes, $row['ID']);
}
$votes = implode(",",$votes);
echo $votes;
+---------------------+
|    COMMENT_VOTES    |
+----+---------+------+
| ID | ITEM_ID | VOTE |
+----+---------+------+
| 1  | 12      | 1    |
| 2  | 8       | 0    |
| 3  | 3       | 1    |
| 4  | 22      | 1    |
| 5  | 5       | 0    |
| 6  | 5       | 1    |
| 7  | 5       | 1    |
| 8  | 5       | 0    |
+----+---------+------+

Answer 1

我最初的方法与您的方法非常相似，并且像您的方法一样失败了。一些研究表明，这种方法不起作用，因为我们都发现$comments字符串中的每个项目确实需要它自己的占位符和关联的类型字符串，这导致我这样做：

/* output */
$votes=array();
/* original string of IDS */
$comments='1,3,4,5,6,7,11,12,13';
/* create an array from IDS */
$array=explode(',',$comments);
/* create placeholders for each ID */
$placeholders=implode( ',', array_fill( 0, count( $array ), '?' ) );
/* create a type string for each - all going to be `i` */
$types=implode( '', array_fill( 0, count( $array ), 'i' ) );
/* create the sql statement */
$sql=sprintf( 'select `id` from `comment_votes` where `vote` > 0 and `item_id` in ( %s );', $placeholders );
/* create the prepared statement */
$stmt = $db->prepare( $sql );
/* Add the type strings to the beginning of the array */
array_unshift( $array, $types );
if( $stmt ){
    /* bind types and placeholders - 2nd arg passed by reference */
    call_user_func_array( array( $stmt, 'bind_param'), &$array );
    /* execute the query */
    $result=$stmt->execute();
    /* success */
    if( $result ){
        $stmt->store_result();
        $stmt->bind_result( $id );
        $rows=$stmt->num_rows;
        printf( 'rows found: %d<br />',$rows );
        /* add found IDs to output */
        while( $stmt->fetch() ) {
            $votes[]=$id;
        }
        /* tidy up */
        $stmt->free_result();
        $stmt->close();

        /* do something with output */
        printf( '<pre>%s</pre>', print_r( $votes, true ) );
    } else{
        exit('Error: No results');
    }
} else exit('Error: Prepared statement failed');

Answer 2

由于某种原因，我无法让绑定工作。但是，我通过使用$stmt = $db_conn->connect->prepare("SELECT ITEM_ID FROM COMMENT_VOTES WHERE VOTE > 0 AND ITEM_ID IN ($comment_ids)");让它在没有绑定的情况下工作