Links to Additional Data

   

What is a Link?

   
  A databank entry may contain references to other databanks, and vice versa. In SRS these relationships are known as links and can be used to extend a query across multiple databanks. Thus you can obtain all the entries in one databank that are linked to an entry (or entries) in another databank.

From a user perspective there are two types of link: hypertext links and index links (query links).

Hypertext links are links between entries which are displayed as hypertext. These are hardcoded into SRS and you can use them whenever you wish. They are useful for examining entries that are referenced directly from entries.

Index links are built into the SRS indices at the same time as databanks are added. They allow you to construct queries using relationships between databanks. They require SRS to search through entries or indices in other databanks, looking for matches.

It is assumed that you are already familiar with hypertext links, so only a limited demonstration of them is given in this chapter (see section "Hypertext Links"). The remainder of this chapter is devoted to explaining index links.