I have a table like
Diesel(id, supplier, operator, machine, taken_time, given_time)
There are 2 kinds of transaction:
1) Suppliers gives diesel to operator
2) Operator gives diesel to machine
My problem is when supplier gives diesel to operator then the machine is null and when operator gives diesel to machine then supplier column is null,
but I don't want to make supplier and machine column to accept null. How do I partition my table?