I think you might want a few more tables. You can't keep much data (or keep much data normalized) with what you've got. I'd do something like this.
customers cust_id (PRIMARY KEY) l_name f_name acct_bal stocks stock_id (PRIMARY KEY) name price shares_total shares_avail transactions trans_id (PRIMARY KEY) seller_id buyer_id share_id share_price share_volume trans_date You could potentially use two tables for transactions (sales, purchases), which might be a good idea if there can be multiple buyers for a single stock sale. It's just as easy to declare each a different transaction, though, which may or may not be what you want. You might want to consider some books on data modeling. The books by Len Silverston are supposed to be good. I can't give my opinion bcs they haven't arrived yet, but I bought both based on the great user reviews at Amazon. Here are links to both. http://www.amazon.com/exec/obidos/tg/detail/-/0471380237/102-5674589-9040158 http://www.amazon.com/exec/obidos/tg/detail/-/0471353485/102-5674589-9040158 Good luck! Edward Dudlik Becoming Digital www.becomingdigital.com ----- Original Message ----- From: "Thomas Kvamme" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, 10 June, 2003 07:17 Subject: Tips & Hints regarding DB/App design Hi All, Needs some tips & hints on how to "BEST" design a spesific database. I have a customer table containing the following fields (just an example): CustomerID - The customers ID Number AccountBalance - The customers Account Blanace / or available funds if you like StockVolume - The number of Stocks hold by the customer Now I want to make an application where all the customer can trade stocks with each other. My first idea was to use 2 tables 1 table holding all the stocks on sales and another table holding the stocks for bying. example: Table: stocksales CustomerID StockVolume SalesPrice Table: stockpurchase CustomerID StockVolume PurchasePrice This application will of course be used by many customers at the same time... How to best handle this in MySQL ? What if several customers tries to buy the same stocks at the same time ?? Any locking methods? Any hints & tips to best design such an database and/or application I'll appreciate it. I'm open for any suggestions. If it does matter: I'm going to use MySQL & Delphi Enterprise 6 Kind Regards Thomas Kvamme -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]