MySQL查询返回对象，但我需要字符串

Question

I have a website with a form. The user first inputs a name and email into the database (I've got this working) and then he can input a name to search in the database and get a photo with the email. I've got the $return value but it is an Object, and in the image creation method I need it to be a String. I've tried to convert it with a cast but it doesn't work. (I've tried outputing it first)

Here's the HTML:

<form name="getEmail"
action="getEmail.php"
method="GET">
Name: <input type="text" name="getEmail" id="getEmail" value="Email..." maxlength="100"         size="20" onclick="this.value=''" />

Here's the PHP:

<?php
$con=mysqli_connect("localhost","root","","assignment1");

if (mysqli_connect_errno()) {
echo "Could not connect to the mySQL database: " . mysqli_connect_error();
}



// create a 100*30 image
$im = imagecreate(100, 30);

// white background and blue text
$bg = imagecolorallocate($im, 120, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 255);

$name=$_GET['getEmail'];
$result = mysqli_query($con,"SELECT email FROM Users WHERE name='$name' ");


echo (String)$result;
// write the string at the top left
imagestring($im, 5, 0, 0,$result, $textcolor);

// output the image
header("Content-type: image/png");
imagepng($im);


mysqli_close($con);
?>

Answer 1

You have not fetched your result that's why you are getting a mysqli_result object .Use mysqli_fetch_assoc() to mysqli_fetch_array() :

$result = mysqli_query($con,"SELECT email FROM Users WHERE name='$name' ");
while ($row = mysqli_fetch_array($result))
      echo $row['email'];

Answer 2

Use this:

$q = mysqli_query($con,"SELECT *
FROM Users WHERE
name='$name' ");

$ar = mysqli_fetch_assoc($q);
$result = $ar['email'];

echo $result;

When you use:

$result = mysqli_query
($con,"SELECT email
FROM Users WHERE
name='$name' ");
echo (String)$result;

You aren't actually selecting the value of the 'email' column for that row, but the full object. What you want to do is select everything from the row, and form an array from this. That way you can then select the 'email' value from this array.