possible ?: mysql row to an if condition - php

Question

hi guys im trying to insert a mysql data to a variable that will set an if condition depending on the result. is this possible, am i doing it right? what is the right way to do it ? what i want to achieve is to validate if there's a equal value given by the user inside my mysql rows.
$db = mysql_connect('localhost','test','');
if (!$db)
{
print "<h1>Unable to Connect to MySQL</h1>";
}
$dbname = 'test';
$btest = mysql_select_db($dbname);
if (!$btest)
{
print "<h1>Unable to Select the Database</h1>";
}
$sql_statement = "SELECT * ";
$sql_statement .= "FROM registered_email ";
$result = mysql_query($sql_statement);
$outputDisplay = "";
$myrowcount = 0;
if (!$result) {
$outputDisplay .= "<br /><font color=red>MySQL No: ".mysql_errno();
$outputDisplay .= "<br />MySQL Error: ".mysql_error();
$outputDisplay .= "<br />SQL Statement: ".$sql_statement;
$outputDisplay .= "<br />MySQL Affected Rows: ".mysql_affected_rows()."</font><br />";
}
else{
$numresults = mysql_num_rows($result);
for ($i = 0; $i < $numresults; $i++)
{
$row = mysql_fetch_array($result);
$id = $row['id'];
$sentEmailClients = $row['email'];
$outputDisplay.= "".$sentEmailClients."<br />";
}
}
and here what im trying to achieve, btw is $clientEmail has a default values so dont worry about that.
if($clientEmail === $outputDisplay){
...... some codes..........
}
else{
....... some codes.......
}

Answer 1

you can use mysql row to compare with your user input. you can add condition, while you'r getting row value for the email inside the loop.
$email_exist = 0;//define the default value.
for ($i = 0; $i < $numresults; $i++)
{
$row = mysql_fetch_array($result);
$id = $row['id'];
$sentEmailClients = $row['email'];
$outputDisplay.= "".$sentEmailClients."<br />";
//my code start here
if($sentEmailClients == $clientEmail)
$email_exist = 1;
}
//outside the loop
if($email_exist == 1) {
//..........write some code.......
}else{
//........write some code.......
}

Answer 2

why don't you use a while loop?
make sure to update to mysqli_* because mysql_* is deprecated and is going to get removed on php 7.0
$email_exist = 0;//define the default value.
while ( $row = mysql_fetch_assoc($result) ) // you are using associative array and not the indexed once tho you should go for mysql_fetch_assoc
{
$id = $row['id'];
$sentEmailClients = $row['email'];
$outputDisplay.= "".$sentEmailClients."<br />";
//my code start here
if($sentEmailClients == $clientEmail)
$email_exist += 1; //maybe it exist more than once?
}
//outside the loop
if($email_exist == 1) {
//..........write some code.......
}else{
//........write some code.......
}
or you can do something more simple like this
$query = "select email from tablename where email='$clientemail'";
$result = mysql_query($query);
$count = mysql_num_rows($result);
if($count > 0) {
// email exists
} else {
// doesn't exist
}