php - 无法获取 PHP 变量的 MySQL 表条目

Question

我真的希望我不只是愚蠢。我正在尝试根据用户 ID 从现有数据库中检索两个值。我一直在尝试一些不同的事情，所以我有一些注释代码，以防万一我很接近!

我使用 select 语句来获取值，然后尝试将它们传递给 PHP 变量。我从数据库获取值，只是不将它们设置为 PHP 变量。

<?php
//declare database variables
header('Content-type: text/html; charset=utf-8');
 $username = "ishuttle";
$password = "";
$hostname = "localhost"; 
$dbname = "ishuttle_taxi-location";

$conn = mysql_connect($hostname, $username, $password);
if(! $conn )
{
  die('Could not connect: ' . mysql_error());
}



//search database for driver location
 
 mysql_select_db('ishuttle_taxi-location');
 
 $sql = "SELECT _id, Latitude, Longitude
FROM driver_location
WHERE _id = 2";




$retval = mysql_query( $sql, $conn );
if(! $retval )
{
  die('Could not get data: ' . mysql_error());
}
while($row = mysql_fetch_assoc($retval))
{
    echo "Lat :{$row['Latitude']}  <br> ".
         "Long: {$row['Longitude']} <br> ".
         "--------------------------------<br>";
} 
echo "Fetched data successfully\n";



$Lat = $retval[1];
$Long = $retval[2];
echo "$Lat";



?>

提前干杯:)

Answer 1

在while循环内分配变量。改变

while($row = mysql_fetch_assoc($retval))
{
    echo "Lat :{$row['Latitude']}  <br> ".
         "Long: {$row['Longitude']} <br> ".
         "--------------------------------<br>";
} 

至

while($row = mysql_fetch_assoc($retval))
{
         $Lat = $row['Latitude'];
         $Long = $row['Longitude'];
         echo "Lat :{$row['Latitude']}  <br> ".
         "Long: {$row['Longitude']} <br> ".
         "--------------------------------<br>";
}