php - 在php中使用MySQL获取计数值

Question

我正在尝试用 php 编写一个非常简单的查询。

$conn = createConnection();
$sql = "select count(username) from passenger where username = '$passengerId' and password ='$password'";
$result = mysql_query($sql);
$count = mysql_result($result, 0);

echo $count;
if ($count == 1)
    echo "true == 1";
else 
    echo "false != 1";

echo print_r(mysql_result($result, 0));
echo $count;

最后，echo print_r(mysql_result($result, 0)) 按预期给出了 1，但 echo $count 不打印任何内容。 if 语句还给我 false != 1。我不确定这里发生了什么类型的问题。

Answer 1

试试这个:

<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$sql="select count(username) as totalUser from passenger where username = '$passengerId' and password ='$password'";
$result=mysqli_query($con,$sql);

// Associative array
$row=mysqli_fetch_assoc($result);
printf ("%s",$row["totalUser"]);

// Free result set
mysqli_free_result($result);

mysqli_close($con);
?>

看看这是否能解决您的问题。