XSLT for Dummies

Chapter 14

Keys and Cross-Referencing

In This Chapter

Finding out about cross-referencing

Using xsl:key and key() together

Using keys with multiple source documents

I remember the first time I ever heard the term cross-reference. I was in school, scouring through the library’s card catalogue, trying to find some obscure book on Ancient Greece. With today’s technology, cross-referencing has been transformed from the kind of labor-intensive process that I faced in that dusty ol’ library into a simple, point-and-click motion on a computer. (Did I also tell you that I had to walk two miles to school each day in a foot of snow in bare feet? Well, I tell my kids that anyway.)

The Web is built on top of this notion of cross-referencing. The reason is obvious: Storing all the information available on the Web in a single gigantic page makes no sense, of course, because such a page would be unusable. Instead, related Web pages are linked together using hypertext.

Relational databases, such as Microsoft Access, are another example of how you can effectively cross-reference related information. For people who need to work with even small amounts of data, storing data across multiple tables ...