Obviously, it is vital that all three of these queries occur. The whole order would be worthless, and your data's consistency would be compromised. Using transaction locking on these three queries would prevent this problem. Different databases offer various levels of transaction locking, so it is important to look at this feature carefully. Security Security is always a concern when the Internet is involved.
Most databases support some level of security, but features vary widely.
Some databases integrate with existing security systems in the operating system on which the database runs. Others contain a security framework within the database itself. The bottom line is that access to a Web-enabled database must be made available only to those who need it. This restriction is imperative for databases that contain sensitive data such as credit card numbers. If your database runs on its own machine, separate from the Web server, then you have an extra layer of security.