Catálogo de publicaciones - libros

You can now print out reports from your database — membership lists, monthly sales reports and personal phone directories are just a few clicks away.

The basic structure of the book database is now complete; the tables have been built and the joins are in place between them. All it lacks is some data. Being the amiable types we are, you’ll find a file called chap16end.mdb containing a database of an identical structure to the one described in this chapter and, what’s more, it contains data. When you look at the table view of this data, you’ll see that expand buttons appear alongside records in the Category, Publisher and Author tables, placed there automatically by Access.

The bigger the database, the more important it is to design it from the outset with a multi-table structure. Databases have a habit of growing and becoming more complex. Often what happens is that users find a database application easy to use and want it to do more and to store details of other aspects of the business. As the complexity increases, it becomes more likely that you’ll encounter the four problems outlined at the start of this chapter. The time and effort spent in redesigning the contents of a single table into a series of tables will almost invariably be less than that taken to work around the problems.

If the Table Analyzer doesn’t produce the results you hope for, designing from scratch is the next step. Creating a database from the ground up also gives you a much greater insight into the way a multi-table database works.

Once you’ve identified the various objects about which data is stored and constructed tables to contain those objects, the next stage is to determine how the tables should act together to form the whole database. No prize is offered for guessing that this happens in Chapter 15.

With queries you can pull selected information out of a database and in this chapter we’ve introduced that most straightforward and most useful type of query, the Select query that allows you to select exactly the information you require. Make-Table queries are rather less commonly used but can be very useful on occasions.

The database constructed so far is contained in the file chap4end.mdb.

Building forms is quick and easy using the Form wizard and AutoForm while for more adventurous forms, the Form Design tool provides the needful. As we’ve said, there’ll be a lot more about the Form Design tool in Chapters 10 and 11 as this chapter contains only a brief introduction. Using the wizard and the Design view in conjunction speeds up development time as you can start with a wizard-generated form that’s almost perfect and then fine tune it with the tools in the Design view.

You can now print out reports from your database — membership lists, monthly sales reports and personal phone directories are just a few clicks away.

The basic structure of the book database is now complete; the tables have been built and the joins are in place between them. All it lacks is some data. Being the amiable types we are, you’ll find a file called chap16end.mdb containing a database of an identical structure to the one described in this chapter and, what’s more, it contains data. When you look at the table view of this data, you’ll see that expand buttons appear alongside records in the Category, Publisher and Author tables, placed there automatically by Access.

The bigger the database, the more important it is to design it from the outset with a multi-table structure. Databases have a habit of growing and becoming more complex. Often what happens is that users find a database application easy to use and want it to do more and to store details of other aspects of the business. As the complexity increases, it becomes more likely that you’ll encounter the four problems outlined at the start of this chapter. The time and effort spent in redesigning the contents of a single table into a series of tables will almost invariably be less than that taken to work around the problems.

If the Table Analyzer doesn’t produce the results you hope for, designing from scratch is the next step. Creating a database from the ground up also gives you a much greater insight into the way a multi-table database works.

Once you’ve identified the various objects about which data is stored and constructed tables to contain those objects, the next stage is to determine how the tables should act together to form the whole database. No prize is offered for guessing that this happens in Chapter 15.

Time and effort go into collecting data and filling a database with it. Queries are how you make your database work for you; they’re the payoff once all the hard work has been done. Having put the data in, queries are how you get information out.

As we progress through the delights of querying, some of the examples may sound a little trivial. Indeed they are, but they’re there to demonstrate the basic task that each type of query performs. Once you understand the principle of each, as your database grows you’ll meet more and more occasions when they can be pressed into service.

Combined with forms and reports, queries become even more powerful and flexible. Experimentation is the key: time spent playing with queries and their adjuncts is rarely wasted.

Building forms is quick and easy using the Form wizard and AutoForm while for more adventurous forms, the Form Design tool provides the needful. As we’ve said, there’ll be a lot more about the Form Design tool in Chapters 10 and 11 as this chapter contains only a brief introduction. Using the wizard and the Design view in conjunction speeds up development time as you can start with a wizard-generated form that’s almost perfect and then fine tune it with the tools in the Design view.