1. Open the report in the Crystal Reports application
  2. Select Database > Database Expert from the upper toolbar
  3. Select the Links tab
  4. Double-click on the link (black line running between the tables) to be changed
  5. In the Link Options window change to the desired join type (example: Left Outer Join) *
  6. Click OK
  7. Repeat steps 3 - 5 if additional table joins need to changed
  8. Click OK to close the Database Expert
  9. Click OK to Refresh the report
* If the Join Type area is grayed out, unmark the Return all rows before joining checkbox. Typically this happens after a report was converted from an older version of Crystal to a newer one (example: Crystal 8.5 to Crystal XI).

Link Options window in Crystal Reports