php-mysqli查询未执行

stmt不会插入也不会更新数据

<?php
if(isset($_GET['name']) and isset($_GET['herosize']) and isset($_GET['herocolor']) and isset($_GET['platform']))
{
    echo "OKAY:".$_GET['name'].",OKAY:".$_GET['herosize'].",OKAY:".$_GET['herocolor'];
    $con = mysqli_connect("127.0.0.1","####","########","phpmyadmin");
    if (!$con)
    {
        die('Could not connect: ' . mysql_error());
    }
    $queryCreateUsersTable = "CREATE TABLE IF NOT EXISTS `DGMOD` (
    `ID` int(11) unsigned NOT NULL auto_increment,
    `USERNAME` varchar(255) NOT NULL default '',
    `PLATFORM` varchar(255) NOT NULL default '',
    `CONFIG` varchar(255) NOT NULL default '',
    PRIMARY KEY  (`ID`)
)";
    mysqli_query($con,$queryCreateUsersTable);

    $stmt = mysqli_prepare($con,"IF EXISTS (SELECT * FROM DGMOD WHERE USERNAME = ? AND PLATFORM = ?) 
THEN
UPDATE DGMOD SET USERNAME = ?, PLATFORM = ?, CONFIG = ? WHERE USERNAME = ? AND PLATFORM = ?
ELSE 
INSERT INTO DGMOD (ID,USERNAME, PLATFORM, CONFIG) VALUES('1',?,?,?)");
    mysqli_stmt_bind_param($con,'ssssssssss',$name1,$platform1,$name2,$platform2,$config2,$name3,$platform3,$name4,$platform4,$config4);
    $name1=$name2=$name3=$name4=$_GET['name'];
    $config2=$config4=$_GET['herosize']."+".$_GET['herocolor'];
    $platform1=$platform2=$platform3=$platform4=$_GET['platform'];
    mysqli_stmt_execute($stmt);
    mysqli_stmt_close($stmt);
    mysqli_close($con);
}
else
{
    die("NO"); 
}
?>

警告：-

Warning: mysqli_stmt_bind_param() expects parameter 1 to be mysqli_stmt, object given in C:'Program Files'VertrigoServ'www'test.php on line 26
Warning: mysqli_stmt_execute() expects parameter 1 to be mysqli_stmt, boolean given in C:'Program Files'VertrigoServ'www'test.php on line 30
Warning: mysqli_stmt_close() expects parameter 1 to be mysqli_stmt, boolean given in C:'Program Files'VertrigoServ'www'test.php on line 31