如何为要插入数据库SQL的许多股票添加ID

Question

I have a dynamic add form field function to add many stock in 1 order to database.

However I was unable to insert the same order_id for the order that contain many stock. I need to use the order_id to print back the order detail

ordertable
--------------------------------------------------------
| order_id | order_item_id | item_name | item_quantity |
--------------------------------------------------------

stocktable
-----------------------------------------------------
| item_id | item_name | item_descript | item_quantity |
-----------------------------------------------------

 <?php  
 require_once('../config.php');

 $number = count($_POST["item_name"]); 
 $item_name=$_POST['item_name'];
 $item_quantity=$_POST['item_quantity'];
 $order_id = uniqid();

 if($number > 0)  
 {  
  for($i=0; $i<$number; $i++)  
  {  
       if($item_name[$i]!="" && $item_quantity[$i]!="")  
       {  
            $sql = "INSERT INTO ordertable(order_id,item_name,item_quantity) 
             VALUES('$order_id','$item_name[$i]','$item_quantity[$i]')";  
            mysqli_query($conn, $sql);  
       }  
  }  

  }   
  $conn->close();
  ?> 

Answer 1

Your schema needs some changes. stocktable contains a list of stock items. ordertable should contain a list of orders, and you are missing a orderdetailtable which contains each of the stock items for a given order.

The problem is that in your schema, you have the order table, with the primary key of order_id and you are expecting to put all the order line-items in with the same order_id ... This isn't going to work.

Create a new table to hold the order line-items, and have the order table with the order-specific information, such as customer, date, etc. The order detail table can be seen as a link table between orders and stock items.

ordertable
------------------------------
| order_id | order_date | ...
------------------------------

orderdetailtable
----------------------------------------------------------
| order_detail_id | order_id | stock_id | order_quantity | 
----------------------------------------------------------

stocktable
--------------------------------------------------------
| stock_id | item_name | item_descript | item_quantity |
--------------------------------------------------------

UPDATE The code above will need to change as well, to cater for the new database structure.

...
if($number > 0)  
{  
    $sql = "INSERT INTO ordertable(order_id, ...) VALUES('$order_id', ...";  
    mysqli_query($conn, $sql);  

    for($i=0; $i<$number; $i++)  
    {   
        $order_detail_id = uniqid();
        if($item_name[$i]!="" && $item_quantity[$i]!="")  
        {  
            $sql = "INSERT INTO orderdetailtable(order_detail_id,order_id,stock_id,item_quantity) 
               VALUES('$order_detail_id','$order_id','$item_id[$i]','$item_quantity[$i]')";  
            mysqli_query($conn, $sql);  
    }  
}
...

Answer 2

The problem is that you are using uniqid() , which is not appropriate for a table id for several reasons, but the relevant one to your problem is that it will return not an integer but an alphanumeric string like this:

59f9a69367e7f

When you try to use that value as the order_id MySQL try to convert it to number stopping at the first non numeric character, so you always get "59".

The simplest methods for fixing this is define the order_id column with AUTO_INCREMENT , in this way MySQL will generate automatically an unique identity for new rows. If you need to get that id for later use you can get it using mysqli_insert_id() .

Note that when inserting in tables with auto incremented id you skip the id column from the column list, in your case you will use:

INSERT INTO ordertable (item_name,item_quantity)

As a final note, you code is vulnerable to SQL injection , you should use mysqli_prepare() and mysqli_stmt_bind_param() .