pradeeshkumar

 Profile Answers by pradeeshkumar 

• Aug 19th, 2010

 

In normal join only matching rows from both the master and detail table will be joined and in the case of master outer join all rows from the detail table will be kept and only matching rows from the master table.

For example consider you are joining employee (master) and project (detail) table based on condition emp.id=proj.id, there are high possibilities of unmatching id in both tables.

In such case you might end up in confusion as to populate id from which table (Either master or detail). To avoid such confusion use an expression transformation in the middle that checks and moves id.