3i Infotech Papers: Sample Questions 813 - 814 of 1245

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Question number: 813

» Database » MySQL

Short Answer Question▾

Write in Short

What is Data Model?

Explanation

Data models and retional data model

Data Models and Retional Data Model

Data models and retional data model

  • A Data Model is a logical structure of Database.

  • It describes the design of database to reflect entities, attributes, relationship among data, constrains etc.

Types of data models:

Object based logical Models – Describe data at the conceptual and view levels.

  • E-R Model

  • Object Oriented Model

Question number: 814

» Database » Oracle

MCQ▾

Question

Which of the following is TRUE

1. Host variables are declared anywhere in the program

2. Host variables are declared in the DECLARE section

Choices

Choice (4) Response

a.

Only 2 is TRUE

b.

1 & 2 are TRUE

c.

1 & 2 are FALSE

d.

Only 1 is TRUE

Answer

a.

Explanation

  • Host variable are data items defined a COBOL program.

  • Host variable is used to pass values to and receive values from a database.

  • Host variables can be defined in the File Section, Working-Storage Section, Local-Storage Section of the COBOL program.

  • Host variable declarations are embedded SQL statements “BEGIN DECLARE SECTION” and “END DECLARE SECTION”

Host Variable Are Used in Two Way:

Input host variables

  • Input host variables specify data that will be transfer from the COBOL program to the database.

Output host variables

  • Output host variables hold data that is returned to the COBOL program from the database.

When we use the host variable in a SQL statement before we must declare it.