Lấy userid duy nhất trong vòng lặp + Câu lệnh sql FIND_IN_SET

 Ví dụ:

pid 1 → userid 10
pid 2 → userid 10
pid 3 → userid 9

→ kết quả cần:

9,10

--------------------

$sum = 0;
$json_data = array();
$list_userid = array();

foreach($data_sp as $sp){

    $total = $sp['g_count'] * $sp['g_price'];
    $sum  += $total;
    $pid  = $sp['g_pid'];

    $shopemail = RETURN__CatalogSPShop__shopname($pid);
    $userid    = RETURN__UserID__Email($shopemail);

    /* lưu userid */
    $list_userid[] = $userid;

    $json_data[] = array(
        "gid"      => $sp['gid'],
        "g_pid"    => $sp['g_pid'],
        "g_price"  => $sp['g_price'],
        "g_point"  => $sp['g_point'],
        "g_count"  => $sp['g_count'],
        "g_code"   => $sp['g_code'],
        "g_title"  => $sp['g_title'],
        "total"    => $total,
        "userid"   => $userid,
        "is_view"  => 0
    );
}

/* lấy userid duy nhất */

$list_userid = array_unique($list_userid);

/* nếu muốn dạng chuỗi */

$userid_string = implode(",", $list_userid);

echo $userid_string;

-------------------- 

$list_userid = [10,10,9]

array_unique →

[10,9]

implode →

"10,9"


---------------------

$sql = "SELECT * 
        FROM orders
        WHERE FIND_IN_SET('$userid', order_shopids)
        ORDER BY order_date DESC";

$rs = mysql_query($sql);