Database-MySQL [3i Infotech Placement]: Sample Questions 126 - 128 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 126

Edit

Describe in Detail

Essay▾

Which is the subset of SQL commands used to manipulate Oracle Database structure, including table?

Explanation

Understanding of SQL Command
  • Data definition language is used to manipulate the data structures.
  • Used to create, modify and destroy databases and objects like table and views.
  • Integrity constrains are defined on tables when the table is created.
  • Provide commands for creating and deleting indexes.
  • Data manipulation language can change existing data in the table- Insert, Update and Delete and Merge.
  • CREATE command is used for the table and column definition along with name of each column and the associated data type.

Question 127

Edit

Write in Short

Short Answer▾

How to find out the database name from SQL ⚹ PLUS command prompt?

Explanation

Two method to find the database name from SQL ⚹ PLUS command prompt.

  • Select ⚹ from global_name;

    Or

  • Select name from v $ database;

Question 128

Edit

Write in Short

Short Answer▾

What is an Extension of entity type?

Explanation

Entity Type is Intension and Extension
  • The collections of entities of a particular entity type are grouped together into an entity set
  • It is the number of tuples present in a table at any instance.
  • This is time dependent.

Developed by: