Dear Sir There are few questions below please reply 1- when there is one blank cell like one city name was blank but on the left and right side there is data as well on this row. When you clean this data you delete that blank row entirely. Do you think that it is a loss of left and right data? Similar is for the duplicate name case( may be the name is duplicate but this data belong to someone else having the same name. 2- please when you made the relationship between the parent and children ( one to many) , Why we did that ? What was the target in our mind to make thar relationship and what would be the outcome?for example we made it because we need to see that one specific customer purchased what on which date from which store and by which method and this is the total of his purchased etc.Actually this is the main thing to understand. Please show us the outcome with a single single relationship. Also what would be the erroe indication if we develop a wrong relationship

These are the 3 videos -Right?

One suggestion- for any topic if you can tell us the objective of the task then it will be very good to understand. I mean like developing the communication relationship between the parent and child , what we are looking for ? Why we are developing this relationship and what we will get? In this way we will be having a target in our mind and then reaching to this target will be having a flowchart in our mind.