php - Error when putting Session variable in insert into query -

this question has answer here:

• syntax error due using reserved word table or column name in mysql 1 answer

i'm getting error:

error: insert order (username, productname, qty) values ('denieall.joe', 'wrist watch', '1') have error in sql syntax; check manual corresponds mysql server version right syntax use near 'order (username, productname, qty) values ('denieall.joe', 'wrist watch', '1' @ line 1

<?php session_start(); include("includes/constants.php"); include("includes/functions.php");      if (!isset($_session['username']))     {         redirect_to_home();      }  //conection , select database:      $conn = mysqli_connect(db_server,db_user,db_pass,db_name) or die("error !!!" );       foreach ($_session["cart_products"] $cart_itm)     {          $sql = "insert order (username, productname, qty)          values ('{$_session['username']}', '{$cart_itm['product_name']}', '{$cart_itm['product_qty']}')";          if (mysqli_query($conn, $sql)) {             echo "new record created successfully";         } else {             echo "error: " . $sql . "<br>" . mysqli_error($conn);         }      }         mysqli_close($conn); ?> 

please me problem.

you should use backticks order

not

insert order 

but

insert `order` 

as other reserved word http://dev.mysql.com/doc/refman/5.6/en/keywords.html