Given a ER diagram, answer the question
Question
Summary
We have given an ER diagram where we have a different entity, attribute, connecting line. And the relationship. So Each has its own different sign. And each one has a different value.
Explanation
In the given ER diagram when one element is connected to another, it forms a relationship. So To represent this relationship. There are many different types of relationships available. We have a different entity, attributes, to connect and show the relationship. we have a connecting line. Also, entities have different shapes so do attributes have There are different types of relationships in the ER diagram.
They are as follows.
- One to one relationship
A one-to-one relationship means that entity A and entity B have a common something. And the one element in entity A can only be connected or can behave the same value in entity B.
- One to many relationships
So In this relationship, suppose there are two entities A and B. So the element in entity A can have a link to the many elements in entity B. But elements in entity B can have a link to only one element the entity A.
- Many to many relationships
In this type of relationship, So Suppose there are many elements in the entity A and B. So the elements in entity A can have a relationship with the elements in entity B. And same the elements in entity B can have a relationship to many elements of entity A.
From the above diagram, we get the following tables and their attributes are:
| Table Name | Attributes |
| AIRPORT | Airport_Code, city, state, Name, Scheduled_dep_time, Scheduled_arr_time, Dep_time, Arr_time |
| AIRPLANE_TYPE | Type_name, Max_seats, Company |
| AIRPLANE | Airplane_id, Total_no_of_seats |
| FLIGHT_LEG | Leg_No |
| FLIGHT | Number, Airline, Weekdays |
| FARE | Restrictions, amount, Code |
| LEG_INSTANCE | No_of_availseats, date, customer name, Cphone |
| SEAT | Seat_no |
Also read, Long-distance carrier charge following rate for telephone