It isn't often that you'll need to worry about this, but it is something all Crystal Reporters should know. You can change the default table JOINs in Crystal to mimic the other JOINs available within the SQL syntax;
Within the Visual Linking Expert (Database | Visual Linking Expert), we can create JOINS between the tables that make up our report.
those of us that have more complex needs or a more modular (relational)
database (i.e. many tables) may need to use different kinds of JOINS.
The "default" JOIN type is INNER.
1. Within the Visual Linking Expert, right click on a "link" (right on the line).
2. Select "Options".
At the bottom right of the window, you may select a JOIN type. All the
expected types are listed (i.e. LEFT OUTER, RIGHT OUTER, etc).
Changing this will impact your expected recordcounts. It is advisable
to be familiar with all the JOIN types before modifying. It's always a good idea to write down how many records are being returned before changing the JOIN. That way, you can really see how the JOIN is impacting the report.