Set the user's email in the database by maintaining user - php

Question

This is how I want to find out about the user exists in the database but it will constantly keep themselves it exists when it does not do it.
What I want out of this code is to get the knowledge about the user in the database if it does not make it must clearly say it :)
}
else
{
$email_1 = $_post["email"];
$result = $this->mysqli->query("SELECT * FROM bruger WHERE email='$email_1'");
if(mysqli_num_rows($resut) > 0)
{
//code here!
}
else
{
?>
<div class="article-main-content">
<div class="alert-message" style="background-color:#c22525;"><span class="icon-text">⚠</span><span class="alert-content">Email Findes på hjemmesiden</span></div>
</div>
<?php
}
}
}
and i have try its here:
$email = $_post["email"]
foreach($this->mysqli->query("SELECT * FROM `bruger` WHERE email='$email'") as $row) {
if ($row['email'] !== $email) {
here are all my html code:
<form action="#" enctype="multipart/form-data" method="post">
<table width="100%" cellpadding="5" cellspacing="5">
<tr>
<td><p>Email</p></td>
<td><input type="text" name="email" class="ned_input"></td>
</tr>
<tr>
<td><p>Adgangskode</p></td>
<td><input type="password" name="password_adgangskode_1" class="ned_input"></td>
</tr>
<tr>
<td><p>Adgangskode Gentag</p></td>
<td><input type="password" name="password_adgangskode_2" class="ned_input"></td>
</tr>
<tr>
<td><p>Fornavn</p></td>
<td><input type="text" name="fornavn" class="ned_input"></td>
</tr>
<tr>
<td><p>Efternavn</p></td>
<td><input type="text" name="efternavn" class="ned_input"></td>
</tr>
<tr>
<td><p>Profilbillede</p></td>
<td><input type="file" name="file" /></td>
</tr>
<tr>
<td></td>
<td><input type="submit" name="opret" value="Opret bruger" style="margin-top:10px;"></td>
</tr>
</table>
</form>
EIDT HERE
if ($stmt = $this->mysqli->prepare("SELECT `id` FROM `bruger` WHERE `email`"))
{
$stmt->bind_param('s', $email_indhold);
$email_indhold = $_POST["email"];
$stmt->execute();
$stmt->store_result();
$stmt->bind_result($id);
$stmt->fetch();
$count = $stmt->num_rows;
$stmt->close();
if($count > 0)
{

Answer 1

look the algorithm for this
PHP end
collect POST data first and sanitize the input.
check for the email
SELECT email FROM table WHERE email = '$post_email' LIMIT 1
if result is not empty then go forward
else gives alert of duplicate entry
Database end
to add UNIQUE KEY constraint on your db
ALTER TABLE <table name >
ADD CONSTRAINT uniqueEmail UNIQUE (< `email column` > )
using unique constraint will safe your table,it will give error when someone try to enter duplicate email.So when you execute INSERT query for the table, check what**mysqli_query** returns ( see below )
$qry = "SELECT INTO table (whatever) VALUE (whatever)";
$done = mysqli_query($qry);
check $done, if everything goes fine then it will return TRUE otherwise it will gives mysql_error( may be 1064), so by this way you can also prevent to stop duplicate email address

Answer 2

This code is enough if you are trying to check email id exist or not.
$email_1 = $_post["email"];
$result = mysql_query("SELECT * FROM bruger WHERE email='$email_1' LIMIT 1");
if(mysql_num_rows($resut) > 0)
{
//code here!
//$result contain other column values
}
else
{
//Email id not exist
}