Question

我正在创建一个登录页面，检查数据库中的匹配值，如果SELECT查询返回一个带有用户名和密码的匹配行，那么它将返回一个行数1.当我回显时，我现在编码的方式存储行数的变量由于某种原因会回显26，我不确定原因。

有人会解释我是做错了什么，或者这是否是正常行为以及该值来自何处？

function checkLogin($conn,$myusername,$mypassword,$row,$row1){
   try {  
        $sql = "SELECT COUNT(*) FROM CLL_users WHERE user_name = 'user' AND password = 'XXXX'";
        if ($results = $conn->query($sql)) {

            if($results->fetchColumn() > 0) {

                $sql = "SELECT * FROM CLL_users WHERE user_name = 'user' AND password = 'XXXXX'";
                foreach ($conn->query($sql) as $row)
                {               
                   $rowCount = count($row);
                   echo $rowCount;
                    print ("Username: " . $row['user_name'] . "<br>");
                     print ("Username: " . $row['password'] . "<br>");

                    }

                    echo $count;
          }
        else {
            print "NO ROWS";
        }
        }
        } catch (PDOException $e){
    echo 'Connection failed: ' . $e->getMessage();
}

}

Answer 1

您的代码$rowCount = count($row);正在计算当前行中的列 - 而不是查询返回的行数。

在同一个注释中，您正在回显第二个 count 相关变量$count，但您既不会在代码中声明它也不会增加它。看起来这个人应该计算你循环的行数。如果是这样，您应该在循环之前将其设置为$count = 0;并在其中使用$count++;：

$count = 0;
foreach ($conn->query($sql) as $row) {
    print ("Username: " . $row['user_name'] . "<br>");
    print ("Username: " . $row['password'] . "<br>");
    $count++;
}
echo $count;

此外，您在选择用户之前正在使用PDO的rowCount，并且您正在正确使用它。您可以将结果存储到变量中，并使用它来告知您接收的行数：

$sql = "SELECT COUNT(*) FROM CLL_users WHERE user_name = 'user' AND password = 'XXXX'";
if ($results = $conn->query($sql)) {
    $numRows = $results->fetchColumn();
    if($numRows > 0) {
        ... rest of your code ....

Answer 2

function checkLogin($conn,$myusername,$mypassword,$row,$row1)
{
   try
   {  
       $sql = "SELECT COUNT(*) FROM CLL_users WHERE user_name = 'user' AND password = 'XXXX'";
       if ($results = $conn->query($sql))
       {

           $count = $results->fetchColumn();
           echo "$count\n";

           if($count > 0)
           {
               $sql = "SELECT * FROM CLL_users WHERE user_name = 'user' AND password = 'XXXXX'";
               foreach ($conn->query($sql) as $row)
               {               
                   print ("Username: " . $row['user_name'] . "<br>");
                   print ("Username: " . $row['password'] . "<br>");     
               }
           }
           else
           {
               print "NO ROWS";
           }
       }
   }
   catch (PDOException $e)
   {
       echo 'Connection failed: ' . $e->getMessage();
   }

}

PDO行计数混乱

2 个答案: