The DNA category covers all the technologies involved in building applications in a Windows environment. There is a strong web emphasis here, but Wrox books in this category also cover non-Microsoft technologies that come under the DNA umbrella - such as XML - and database technologies like SQL Server and Access. This tree shows the database section of the DNA technology world.SQL (Structured Query Language) is a way a programmer's application can talk to any database, and customize it. SQL has the advantage of being easy to use and is well tested; it's the logical link between web pages and data storage. It is platform-independent and the primary interface for both Microsoft SQL Server and Oracle.
SQL is a rare thing: it's a long standing industry standard, and is completely compatible with its earlier versions. It will remain the standard for years to come.