HP Intelligent Management Center Standard Software Platform - Manual (Page 670)

SQL Data
Total
Records
Read
For each A
reads in B
Reads A
Selection
Formula Linking/Sub
report
2600 100 (26*100) 26 No Linking
200 100 (2*100) 2 Yes Linking
2600 100 (26*100) 26 No Subreport
200 100 (2*100) 2 Yes Subreport
Data file considerations
When working with data files, one-to-many links can occur when you link
tables in a single report or when you add a subreport to your report.
Linking data files
When retrieving data from linked data files in one-to-many situations, the
program uses the following process:
• If there is a selection formula, the program parses the selection formula
and passes what it can down to the database DLL. This is generally range
limit information. Consider the following record selection formula:
{customer.REGION} in "CA" to "IL" AND
Remainder ({customer.CUSTOMER ID},2)=0
In this formula, the part before the "and" operator contains range selection
criteria for the Region field. The region must fall alphabetically between
"CA" and "IL." The program passes this kind of condition down to either
670 Crystal Reports 2008 SP3 User's Guide
Understanding Databases 25
Linking tables