获取每行MySQL表的特定列中的元素数

Question

我有一个具有数组列的MySQL表，而每个元素都由“，”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。因此，显然我缺少了一些东西。

如果有人指出我的错误，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 !=' '";

您没有将var $ ShowID连接起来，正确的是：

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

Answer 2

感谢所有回答-这是我的最终代码。 也许有更好的方法可以做到这一点，但是它可以工作，所以没关系。

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

$result = mysql_query($SQL);
$myClasses = array(); // make a new array to hold my classes
$totalClasses=0;
$index = 0;

$query = mysql_query($SQL);
$row = mysql_fetch_row($query);
while($row = mysql_fetch_row($query)) // loop
{
    $myClasses[$index] = $row[0];
    $classes = explode(",", $myClasses[$index]);
    $count = 0;
    foreach ($classes as $item) {
       $count++;
    }
    $totalClasses = $totalClasses + $count;
    $index++;
}
echo "<br><b>Number Classes Entered:</b> ".$totalClasses;