php - 如何根据条件计算多行

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因此，我尝试让查询计算该位置的玩家总数(如果他们位于同一位置且在线)。但我当前的查询返回 0。不知道该尝试什么，被卡住了几天。

<?php 
    include('connect.php'); 

            $town = $info['location'];

            $grabTown = mysql_query("SELECT * FROM `location` WHERE `name` = '$town'");
            $t = mysql_fetch_array($grabTown);

            $totPlayers = mysql_query("SELECT COUNT(*) AS player_total FROM `user_info` WHERE `location` = '$town' AND 'online' = '1'");
            $totalPlayers = mysql_fetch_array($totPlayers);
            $playersTotal = $totalPlayers['player_total'];
?>

Answer 1

这是你的问题:

$totPlayers = mysql_query("SELECT COUNT(*) AS player_total FROM `user_info` WHERE `location` = '$town' AND `online` = '1'");

您在引号中使用了“在线”，而不是反引号。