_POST method returns ??? when request utf8 characters - php

Question

i have the following problem... i am building an android app and i regeuest text formated in utf8 (greek chars) from editTexts by using the POST method. The POST method gets the greek chras from the editTexts as '???' and insert them in mysal again as '???'
How will the POST recognize my greek chars???
<?php
// PHP variable to store the host address
$db_host = "localhost";
// PHP variable to store the username
$db_uid = "lolen";
// PHP variable to store the password
$db_pass = "lolen";
// PHP variable to store the Database name
$db_name = "lolen";
// PHP variable to store the result of the PHP function 'mysql_connect()' which establishes the PHP & MySQL connection
$db_con = mysql_connect($db_host,$db_uid,$db_pass) or die('could not connect');
mysql_query("SET character_set_results=utf8", $db_con);
mb_language('uni');
mb_internal_encoding('UTF-8');
mysql_select_db($db_name, $db_con);
mysql_query("set names 'utf8'",$db_con);
// array for JSON response
$response = array();
// check for required fields
if (isset($_POST['k_p']) )
{
$Kwdikos_Proiontos=$_POST['k_p'];
$Proion=$_POST['p'];
$Kwdikos_Tupou=$_POST['k_t'];
//$Tupos=$_POST['t'];
$sql=mysql_query("SELECT * FROM tupoi WHERE Kwdikos_Tupou LIKE '". $_POST["k_t"]."'", $db_con);
while($row = mysql_fetch_array($sql))
{
$output[]=$row['Tupos'];
$re= json_encode($output[0]);
$dd= json_decode($re, true);
}
$result =mysql_query("INSERT INTO proionta(Kwdikos_Proiontos, Proion, Kwdikos_Tupou, Tupos) VALUES('$Kwdikos_Proiontos', '$Proion', '$Kwdikos_Tupou', '$dd')");
//check if row inserted or not
if ($result) {
// successfully inserted into database
$response["success"] = 1;
$response["message"] = "Product successfully created.";
// echoing JSON response
echo json_encode($response);
}
else {
// failed to insert row
$response["success"] = 0;
$response["message"] = "Oops! An error occurred.";
// echoing JSON response
echo json_encode($response);
}
}
else
{
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";
// echoing JSON response
echo json_encode($response);
}
?>
ps. my db is already in utf8 cause i display and add other data in greek, by using SELECT , INSERT, in the db.

Answer 1

Finally i found a solution to my problem, i used GET method instead of POST, and now it works correctly! Thnx for the sql injection tips, i will read more about this issue!