Home > Computer > SQL Database #2 -Questions & Answers

SQL Database #2 -Questions & Answers

SQL Database #2

History of SQL Database

In 1969, IBM researcher Edgar F. Codd defined the relational database model, which became the basis for developing the SQL language. This model is built on common pieces of information (or “keys”) being associated with various data. For example, a username might be associated with an actual name and a telephone number.

A few years later, IBM began working on a new language for relational database management systems based on Codd’s findings. The language was originally called SEQUEL, or Structured English Query Language. Dubbed System/R, the project went through a few implementations and revisions, and the name of the language changed several times before finally landing on SQL.

After beginning testing in 1978, IBM started developing commercial products, including SQL/DS (1981) and DB2 (1983). Other vendors followed suit, announcing their own commercial SQL-based offerings. These included Oracle, which released its first product in 1979, as well as Sybase and Ingres.



Related Link
SQL Database #1-Questions & Answers
Security Tool -Cyber Security # 4
Security Tips – Cyber Security #3
Method Of Defence – Cyber Security #2
Computer Threats – Cyber Security #1

Learning 0f SQL Database

It typically is easier for beginners to learn SQL than it is for them to pick up programming languages like Java, C++, PHP, or C#.

Several online resources—including free tutorials and paid distance learning courses—are available for those who have little programming experience but want to learn SQL. Formal university or community college courses also will provide a deeper understanding of the language.

Some of the free tutorials include W3Schools SQL Tutorial, SQLcourse.com, and Codecademy’s Learn SQL and a course on analyzing SQL business metrics.

Options for paid distance-learning courses include the International Webmasters Association’s (IWA) Introduction to SQL (Using Access) or Introduction to SQL (Using MySQL). IWA’s SQL courses are only four weeks long, but the presence of instructors and weekly assignments make them more structured than self-learning tutorials.

Useful books on SQL for beginners include “SQL: A Beginner’s Guide” and “SQL in a Nutshell.”

Some Important Questions of SQL Database are listed Bellow :


1- What is the use of CASCADE CONSTRAINTS?

Answer: When this clause is used with the DROP command, a parent table can be dropped even when a child table exists.
Explanation:

2- Which function is used to find the largest integer less than or equal to a specific value?

Answer: FLOOR
Explanation:



Related Link
SQL Database #1-Questions & Answers
Security Tool -Cyber Security # 4
Security Tips – Cyber Security #3
Method Of Defence – Cyber Security #2
Computer Threats – Cyber Security #1

3- What is the output of the following query?
SELECT TRUNC(1234.5678,-2) FROM DUAL;

Answer: 1200
Explanation:

4- Which is the subset of SQL commands used to manipulate Oracle Database structures, including tables?

Answer: Data Definition Language (DDL)
Explanation:

5- What operator performs pattern matching ?

Answer: LIKE operator

Explanation:

6- What operator tests column for the absence of data?

Answer: IS NULL operator

Explanation:

7- Which command executes the contents of a specified file?

Answer: START or @

Explanation:



Related Link
SQL Database #1-Questions & Answers
Security Tool -Cyber Security # 4
Security Tips – Cyber Security #3
Method Of Defence – Cyber Security #2
Computer Threats – Cyber Security #1

8- What is the parameter substitution symbol used with INSERT INTO command?

Answer: &

Explanation:

9-Which command displays the SQL command in the SQL buffer, and then executes it?

Answer: RUN

Explanation:

10- What are the wildcards used for pattern matching?

Answer: _ for single character substitution and % for multi-character substitution

Explanation:


Related Link ,See once

SQL Database #1-Questions & Answers
SECURITY TOOLS -Cyber Security # 4
Security Tips – Cyber Security #3
Method Of Defence – Cyber Security #2
Computer Threats – Cyber Security #1
Cyber Security Introduction
Cyber Security
World Wide G.K
Facts around World
Science
Geography
History of the World
>>> CONTACT US < <<

Summary
Article Name=>
SQL Database #2 -Questions & Answers
Description=>
This is the Second Part of SQL Database ,Next Part will Come Soon
Author=>
Publisher Name=>
www.gkaim.com
Admin
Welcome Sir, .. Myself Vikas Chaudhary , i was interested in general knowledge since childhood , so i thought why not to share my knowledge with you, that's why i created this educational blog. Here you find world wide general knowledge of all Latest technology , Science & History Que , and Mysterious fact of the world. Here you also find knowledge about cyber security. Thanks for visit.. keep supporting....keep Loving
https://www.gkaim.com

3 thoughts on “SQL Database #2 -Questions & Answers

  1. Pingback: 2019

Leave a Reply

Your email address will not be published.

%d bloggers like this:
\