php - 获取 MySQL 表的每一行的特定列中的元素计数

Question

我有一个 MySQL 表，其中有一个数组列，而每个元素均由“,”分隔。我尝试获取所有行的总数 (145)

当我运行以下代码时，我得到的 $index 为 145，这是正确的，但 $totalClasses 为 0。所以显然我遗漏了一些东西。

如果有人指出我的方法中的错误，我将不胜感激!

谢谢

维克

echo "<br><b>Number Classes Entered:</b>";
$SQL="SELECT ExhibitorClasses FROM tblShowEntries WHERE ShowID = $ShowID AND ExhibitorClasses IS NOT NULL AND ExhibitorClasses !=' '";


$result = mysql_query($SQL);
$myClasses = array(); // make a new array

$index = 0;
while($row = mysql_fetch_assoc($result)) // loop to get the count
{
     $myClasses[$index] = $row;
     $userclasses = count($myClasses[$index]);
     $totalclasses = $totalclasses + $userClasses;
     $index++;
}

//  $userClasses = explode(",", $myClasses);
//  $totalclasses = count($myClasses);
echo $index . " " . $totalclasses 

Answer 1

在

$SQL="SELECT ExhibitorClasses FROM tblShowEntries WHERE ShowID = $ShowID AND ExhibitorClasses IS NOT NULL AND ExhibitorClasses !=' '";

您没有连接 var $ShowID 正确的是:

$SQL="SELECT ExhibitorClasses FROM tblShowEntries WHERE ShowID = ".$ShowID." AND ExhibitorClasses IS NOT NULL AND ExhibitorClasses !=' '";