Creating a table with a dual primary key

This question may be a little complicated.

I am building a DTS Package that is moving data from our webstore (written in house) to a Warehouse Management System(WMS - Turnkey) and I've encountered a problem. both pieces of software have an orders table and an Ordered_Items table, related by the order_ID (makes sense so far). Here is the problem. The primary key on the webstore's Ordered_Items table is a single column (basically an Identity variable), while the primary key on the WMS's Ordered_Items table is a dual column primary key, between the Order_ID and the Order_LineID, so the data should be stored like:

OrderID Order_LineID
1 1
2 1
2 2
2 3
3 1
3 2
4 1

Get the Idea? So I have to create this new Order_LineID column. How can I accomplish this with a SQL statement?

Thanks!!!!!Does it matter that the destination needs to start at 1 and be sequential? If not, just use the Identity value. Probably too simple.

If you do it in a cursor, you could use a counter and move each record one at a time and use your counter to create the line number.

You could create the line number field in your source and pre-populate it with a process to loop through and assign the line numbers just prior to dumping it to the destination.

Doing it within one SQL statement to move it from one to the other might be impossible.|||Yes, you can create primary key that consists of two columns, or composite primary key.
It is not possible to create dual promary key in SQL server. You may create multiple uniqe index/constraints. But for one talbe, there is only one primary key.|||It is not quite clear what you exactly want to do.

Do you want to add a new column for an existing table as a primary key or is it a whole new table?|||I think we are on the right track (sort of).

I my example, the Order ID's are already assigned (they basically use an Identity Key).

What I need is some sort of query (or activeX script) that will loop through each record, and assign the Order_Line_ID (By the way, I don't care how many SQL statements this takes, as long as it works).

I am querying the Order_Line table, and sorting it by the Order#, so the table will look like this at first:

LineID-Identity | Order#
1 | 12345
2 | 12345
3 | 12345
4 | 12346
5 | 12347
6 | 12347
7 | 12348

The idea is, an order may have multiple lines (you've probably ordered more than one item at a time from some site online)

The counter needs to start over at 1 when it comes to a new order. For example, if the first three records in the Order_Line table are from Order# 12345, the first three rows would be numbered 1, 2 and 3, respectively (that should make sense). Now the tricky part: If the next Order # is 12346, the counter would start at 1 again, like this.

LineID-Identity | Order# | OrderLine#
1 | 12345 | 1
2 | 12345 | 2
3 | 12345 | 3
4 | 12346 | 1
5 | 12347 | 1
6 | 12347 | 2
7 | 12348 | 1

As you can see, this is a new column, so no data is being removed. How do you do this?|||Within SQL, use a cursor and loop through a sorted list of the line items. Use a "current" and "previous" variable to hold the order ID and a counter to hold the new line number. Create the field (null at first), loop through the cursor and using the logic of comparing the last order ID to the current one, assign the line number from the counter, increment the counter, etc. Look up the cursor options you'll need to use to make the cursor editable.