What is the difference between a Weak Entity and a Sub Entity?

Question :

What is the difference between a Weak Entity and a Sub Entity?

A Weak entity depends upon a regular entity for its existence whereas a Sub entity is part of a Regular entity. For example, an entity called Students is used to store all student details. Now, every student is enrolled for a course and there are some students who have taken a break from the course. In this kind of a scenario, we can have a Sub entity called Break-Students, which stores details of all students who have currently taken a break. Note that a Sub entity will contain all the columns of the super-entity from which it is derived. A Weak entity on the other hand has attributes that are different from those of the regular entity on which it is dependent.

Similar Questions

•  What is Django's middleware and how is it used?
  

• What are comments? Name the different types of comments used in Java.
• What are syntax errors? Give two examples.
• What are the different type of errors that may occur in a Java program?
• What is a bug? What is debugging?
• What is an accumulator?
• What is an expression?
• What is an operator? How is the classification of operators based upon?
• What is Type Conversion? Name the two type conversions in Java.
• What are separators?
• How are Decimal, Octal and Hexadecimal integer literals represented in Java?
• State two conventions you should follow while naming a class.
• What two conventions you should follow naming a class?
• State two rules you should follow for naming a class
• Why is a class called an object factory?
• What is an access specifier? Which two access specifier is used in a class declaration?
• Why is a class called a user defined data type?
• State two differences between a class and an object.
• State two differences between fundamental and user-defined data type.
• Explain the statement “Byte code is the object code for the JVM”