Join
          A Join line is automatically created between objects when a new object is dropped over the existing one. Upon creation, a warning icon indicates that join is yet to be defined. Click the icon to open the  configuration window.
         
         There are three main functions:
- Select a Join type.
 - Add Join Rule to define how objects are linked together.
 - Add Constant to define the filtering criteria.
 
Join Type
These Join types are available for selection:
- INNER
 - LEFT
 - RIGHT
 - FULL
 
The Inner join is selected by default. Click the required join type icon to change the default.