Books.xml:
ABC Author Name 2020 100.00 XQuery Book Author 1 Author 2 2005 300.00 Sociology 1 Author Name 2010 250.00 Current Affairs Author Name 2004 500.00 Science Book Author 1 Author 2 Author 3 2011 150.00
To Select Nodes From “books.xml”:
Functions:
To extract data from XML documents, the functions in XQuery are used.
Example:
doc("books.xml")
Explanation:
In the above example, we are opening the “books.xml” file using the doc() function.
Path Expressions:
To navigate through elements in an XML document, path expressions are used by XQuery.
Example:
doc("books.xml")/bookstore/book/title
Explanation:
In the above example, we are selecting all the title elements in the “books.xml” file using the above path expression. To select the bookstore element, we are using “/bookstore”, to select all the book elements under the bookstore element, we are using “/book” and to select all the title elements under each book element, we are using “/title”. Thus, the below will be extracted by the XQuery above:
ABC XQuery Book Sociology 1 Current Affairs Science Book
Predicates:
To limit the extracted data from the XML documents, predicates are used by XQuery.
Example:
doc("books.xml")/bookstore/book[price>300]
Explanation:
In the above example, we are using the predicate to select all the book elements under the bookstore element with a price element having a value higher than 300. Thus, the below will be extracted by the XQuery above:
Current Affairs Author Name 2004 500.00
