สอบถามเรื่องการเช็คค่าซ้ำก่อน insert และ update sql ครับ

//รับค่าจาก Form //
<input type="hidden" value="<?php echo $ro['id_bill'];?>" name="id_bill_input">
//รับค่าจาก Form //

$strSQL = "SELECT  id_bill , count(id_bill)  count from money_all  WHERE member_id = '$_SESSION[login_true]'";
$objQuery = $conn->query($strSQL) or die( $conn->error . "<br>$sql" );
$ro = $objQuery->fetch_array();

$id_bill = $_POST['id_bill'];
$member_id = $_POST['member_id'];
$total = $_POST['total'];
$submit = $_POST['submit'];
$date = date("Y-m-d",  time());
$id_bill_input= $_POST['id_bill_input'];

if($ro['id_bill'] != $id_bill_input){ ///<----เปลี่ยนรับค่าฟิลด์จาก select มาก่อนเพื่อเช็คว่ามีค่าว่างหรือเปล่า ถ้าไม่มีให้ทำการบันทึกข้อมูลลงไปครับ $id_bill_input 
	$sql ="INSERT into money_all (id_bill , member_id , date , total)
VALUES ('$id_bill' , '$member_id' , '$date' , '$total')";
$query = $conn->query($sql) or die($conn->error . "<br>$sql");
}

1. check code select ถูกไหม?
$strSQL = "SELECT  id_bill , count(id_bill)  count from money_all  WHERE member_id = '$_SESSION[login_true]'";
---------------
$strSQL = "SELECT  id_bill , count(id_bill) [font=Verdana] as  count_bill[/font] from money_all  WHERE member_id = '$_SESSION[login_true]'";

2. check $_GET["id"] ; มาไม่? 
<form name ="frm" action="[font=Verdana]sum.php?id=<?php echo $result["id"]?>[/font]" method="post" > 

3. check ค่า IF ถูกไม่ที่เอามาเปรียบเทียบ
if ('id_bill' != $x){


}
----------------
or num_row
if($x >= 0 )
{
echo "do something";
}else{
echo "do something";
}

<?php 
include("check_user.php");



$id_bill = $_POST['id_bill'];
$member_id = $_POST['member_id'];
$total = $_POST['total'];
$submit = $_POST['submit'];
$date = date("Y-m-d",  time());

print_r($_POST);

$sql = "SELECT  * FROM money_all ";
$query = mysqli_query($conn,$sql) or die ("Error Query [".$sql."]");
while($result=mysqli_fetch_array($query,MYSQLI_ASSOC))  {
$x = $result["id_bill"];
}

if (($id_bill != $x)) {
	$sql ="INSERT into money_all (id_bill , member_id , date , total)
VALUES ('$id_bill' , '$member_id' , '$date' , '$total')";
$query = $conn->query($sql) or die($conn->error . "<br>$sql");

} else   {
	$sql = "UPDATE money_all SET		
		WHERE member_id='$_SESSION[login_true]' AND id_bill = '".$_POST["id_bill"]."' ";
$query = $conn->query($sql) or die($conn->error . "<br>$sql");

	exit();
}




?>

Array ( [submit] => พิมพ์ใบเสร็จแบบ A4 [member_id] => admin [id_bill] => 371 [total] => 2020 [date] => 2018-07-25 ) You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE member_id='admin' AND id_bill = '371'' at line 2
UPDATE money_all SET	WHERE member_id='admin' AND id_bill = '371