Có nhiều biến thể lệnh SQL, một giới thiệu đầy đủ trong số họ chắc chắn ra khỏi phạm vi của cuốn sách này. Toàn bộ cuốn sách được dành đến chủ đề này! Tuy nhiên, tôi sẽ cố gắng Giả sử rằng sau này bạn muốn xóa dữ liệu đó. Một lệnh xóa mẫu là: | CHAPTER 14 PHP and XML It can hardly be argued that the Web has not vastly changed the landscape on which we share information. The sheer vastness of this electronic network has made the establishment of certain standards not only a convenience but a requirement if organizations are ever going to exploit the Web to its fullest capability. XML eXtensible Markup Language is one such standard providing a means for the seamless interchange of data between organizations and their applications. The implications of this are many resulting in the facilitation of media-independent publishing electronic commerce customized data retrieval and many other data-oriented services. In the first part of this chapter I provide a general introduction to XML highlighting the general syntactical elements that comprise the language. The second half of this chapter is dedicated to PHP s XML-parsing capabilities elaborating on its predefined XML functionality and the language s general XML-parsing process. This material is geared toward providing you with a better understanding of both why XML is so useful and how you can begin coming to terms with how PHP can be used to develop useful and interesting XML-based applications. Before delving directly into the issue of XML many newcomers to this subject may find it useful to learn more about the history behind the concepts that ultimately contributed to the development of the XML standard. A Brief Introduction to Markup As its name so implies HTML HyperText Markup Language is what is known as a markup language. The term markup is defined as the general description for the document annotation that instead of being displayed to whatever media the document is destined for is used for describing how parts of that document should be formatted. For example you may want a particular word to be boldfaced and another italicized. You may wish to use a particular font for one paragraph and a larger font size for a header. As I type this paragraph my .
