Access Database Design and Programming, Second Edition

Host Languages

Data are seldom manipulated without some intended purpose. For instance, consider a LIBRARY database consisting of information about the books in a library. If a student wishes to access these data, it is probably with the intention of finding a certain book, for which the student has some information, such as the title. On the other hand, if a librarian wishes to access the information, it may be for other purposes, such as determining when the book was added to the library, or how much it cost. These issues probably don’t interest the student.

The point here is that a DBMS should supply an interface with a high-level language with which programmers can program the database to provide specific services; that is, with which programmers can create database applications. Thus, when a student logs onto a library’s computer to search for a book, he or she may be accessing a different database application than the librarian might access. The language that is used for database application programming is the host language for the DBMS. As mentioned earlier, a host language may be a traditional programming language, such as C or COBOL, or it may be an application-level language, such as Microsoft Access or Visual Basic, as it is for the Jet DBMS.

In fact, the Jet DBMS is so tightly integrated into both of these applications that it is hard to tell where one leaves off and the other begins. Put another way, it sometimes seems as though Microsoft Access is the Jet DBMS, whereas ...