Mastering Crystal Reports 9 [Electronic resources] نسخه متنی

Database Files

Crystal Reports has the ability to work with certain types of databases directly through the use of a single data access layer with no reliance on SQL or ODBC. In other words, if Crystal Reports is installed on your computer, you can get to certain kinds of databases without doing any connectivity work at all. These databases are referred to as PC databases or direct-access databases. They do not come under the client/server model of databases.

PC databases are typically used to build databases that will be used by a single user at a time and are generally not used to store enterprise-wide data. The list of PC databases includes:

Clipper

dBASE

FoxPro

Microsoft Access

Paradox

Pervasive

To work with any of these types of databases, all you need to do with the Database Expert is locate the file on the computer using the built-in browse window. The database is then added below the Database Files connectivity folder in the Database Expert, as shown in Figure 10.27.

Figure 10.27. Database Files connectivity

There is a limitation on PC databases: You cannot switch from one type of data source to another regardless of whether the database table and fields are identical or not. If you predict a need to switch database types down the road, using ODBC to make the connection is a safer choice.