Câu trả lời cho những câu hỏi và giải thích lý do tại sao mỗi sự lựa chọn câu trả lời là đúng hay sai là nằm trong phần "Câu trả lời" ở cuối của cuốn sách Các loại hình đơn đặt hàng chỉ số về thể chất của các hàng trong một bảng? | 258 Chapter 8 Managing XML Data the data in the XML structure. XML Schema enables you to declare optional sections inside the schema or generic types that accept any XML fragment. This capability means you can represent not only structured data but also semistructured and unstructured data. Fourth XML data is searchable. Because of XML s hierarchical structure you can apply multiple algorithms to search inside tree structures. XQUERY and XPATH are query languages designed to search XML data. And fifth XML data is extensible. You can manipulate XML data by inserting modifying or deleting nodes. This capability means that you can create new XML instances out of existing XML structures. NOTE Data representation types Here are definitions of the three data representation types Structured data Homogeneous static data structure in which all instances of the data follow the same structure. Semistructured data Heterogeneous data structure that can contain dynamic or optional structures. Instances can look completely different from each other but still conform to the same schema. Unstructured data Heterogeneous data that does not conform to a schema. In XML data can exist without having a schema to define its structure. Applications that manipulate XML execute a variety of actions on data such as creating new XML documents filtering an XML document and extracting relevant nodes based on a filter expression transforming an XML fragment into another XML structure and updating or modifying the current data inside the XML structure. The way applications store XML data affects which of these possible actions are at your disposal. SQL Server 2005 enables you to store XML data in two ways As XML in the database in a text column As XML in the database in an XML data type column MORE INFO Storing XML data as relational data Lesson 5 in this chapter covers storing data as a relational representation and applying composition and shredding techniques to transform relational data into .
