Database-MySQL [3i Infotech Placement]: Sample Questions 20 - 21 of 162

Glide to success with Doorsteptutor material for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.

Question 20


Write in Short

Short Answer▾

What is SDL (Storage Definition Language) ?


  • SDL (Specification and Description Language) is a program design and implementation language that is used to build real-time event-driven systems that involve parallel processing .
  • Some advantages of SDL, according to its proponents, include mathematical rigor, clarity, consistency, portability, scalability, and the ability to interface with other languages.
  • It is described as a graphical language that eliminates ambiguity.

Question 21


Describe in Detail


What is an Entity type?


  • An entity is represented or defined by set of attributes.
  • Attributes are the properties used to describe an entity.

Types of Entity:

  • Strong Entity Types
  • Recursive Entity Types
  • Weak Entity Types
  • Composite Entity Types or Associative Entity Types
  • SuperType and SubType Entities

Different Entity Type in ER Diagram

Table of Different Entity Type in ER Diagram
Entity Type in Image
Strong Entity Type
Strong Entity Type
Weak Entity Type
Weak Entity Type
Recursive Entity Type
Recursive Entity Type
Composite Entity Type
Composite Entity Type (or)

Associative Entity

Subtypes and Supertypes
Subtypes and Supertypes

Developed by: