Chapter 8: Analyzing with Advanced Selection Criteria

Overview

Creating a simple report is as quick as choosing tables, dragging and dropping fields on the report, and clicking the Preview button. However, if you perform only those few steps, you may have a much larger report show up than you bargained for! One important step missing is record selection. If you don t enter some record selection criteria, every record that exists in the tables you choose will appear on the report.

In the case of a small PC-type database with, say, 1,000 records, this won t be terribly time- or resource- intensive . However, if you re connected to a large SQL database with potentially millions of records, the consequences of not including record selection will probably be felt on your network, and they will certainly be felt on your desktop PC. Since Crystal Reports needs to store the data that makes up a report somewhere, you may run out of memory or temporary disk space in such a situation. Regardless of these concerns, your report will be terribly slow, and probably not very useful, if you have that many records on the report.

Virtually all reports will need record selection criteria. You may want to limit the report to only USA customers, only orders placed in 2001, or only invoices that are more than 30 days past due. Record selection criteria can be used to limit your report to any of these sets of records. In any event, it s very wise to apply your record selection criteria early on in your report design process ”probably before you preview or print the report.