Skip to main content

What is database and SQL?

In simple words data can be facts related to any object in consideration.For example your name, age, height, weight, etc are some data related to you. A picture , image , file , pdf etc can also be considered data.

What is a Database? 

Database is a systematic collection of data. Databases support storage and manipulation of data. Databases make data management easy. Let's discuss few examples. An online telephone directory would definitely use database to store data pertaining to people, phone numbers, other contact details, etc.Your electricity service provider is obviously using a database to manage billing , client related issues, to handle fault data, etc. Let's also consider the facebook. It needs to store, manipulate and present data related to members, their friends, member activities, messages, advertisements and lot more. We can provide countless number of examples for usage of databases .

What is a Database Management System (DBMS)?

Database Management System (DBMS) is a collection of programs which enables its users to access database, manipulate data, reporting / representation of data .
It also helps to control access to the database.
Database Management Systems are not a new concept and as such had been first implemented in 1960s.Charles Bachmen's Integrated Data Store (IDS) is said to be the first DBMS in history.
With time database technologies evolved a lot while usage and expected functionalities of databases have been increased immensely.

Types of DBMS: 

Let's see how the DBMS family got evolved with the time. Following diagram shows the evolution of DBMS categories.

Hierarchical - 

This type of DBMS employs the "parent-child" relationship of storing data. This type of DBMS is rarely used nowadays. Its structure is like a tree with nodes representing records and branches representing fields. The windows registry used in Windows XP is an example of a hierarchical database. Configuration settings are stored as tree structures with nodes.

Network DBMS - 

This type of DBMS supports many-to many relations. This usually results in complex database structures. RDM Server is an example of a database management system that implements the network model.

Relational DBMS -

This type of DBMS defines database relationships in form of tables, also known as relations. Unlike network DBMS, RDBMS does not support many to many relationships.Relational DBMS usually have pre-defined data types that they can support. This is the most popular DBMS type in the market. Examples of relational database management systems include MySQL, Oracle, and Microsoft SQL Server database.

Object Oriented Relation DBMS - 

This type supports storage of new data types. The data to be stored is in form of objects. The objects to be stored in the database have attributes (i.e. gender, ager) and methods that define what to do with the data. PostgreSQL is an example of an object oriented relational DBMS.

What is SQL?

Structured Query language (SQL) pronounced as "S-Q-L" or sometimes as "See-Quel"is actually the standard language for dealing with Relational Databases.
SQL programming can be effectively used to insert, search, update, delete database records. Although SQL is an ANSI (American National Standards Institute) standard, there are different versions of the SQL language.
However, to be compliant with the ANSI standard, they all support at least the major commands (such as SELECT, UPDATE, DELETE, INSERT, WHERE) in a similar manner.
Note: Most of the SQL database programs also have their own proprietary extensions in addition to the SQL standard!

What Can SQL do?

  • SQL can execute queries against a database
  • SQL can retrieve data from a database
  • SQL can insert records in a database
  • SQL can update records in a database
  • SQL can delete records from a database
  • SQL can create new databases
  • SQL can create new tables in a database
  • SQL can create stored procedures in a database
  • SQL can create views in a database
  • SQL can set permissions on tables, procedures, and views
REFERENCES :
1. https://www.guru99.com/introduction-to-database-sql.html

Comments

Post a Comment

Top 5 Most Read Posts

Who is Peter Lynch and what is his philosophy in equity market investment? 25 Golden Rules of the most successful Fund Manager.

Peter Lynch (born January 19, 1944) is an American investor, mutual fund manager, and philanthropist. As the manager of the Magellan Fund at Fidelity Investments between 1977 and 1990, Lynch averaged a 29.2% annual return, consistently more than doubling the S&P 500 stock market index and making it the best-performing mutual fund in the world. During his 13 year tenure, assets under management increased from $18 million to $14 billion. He also co-authored a number of books and papers on investing and coined a number of well known mantras of modern individual investing strategies, such as Invest in what you know and ten bagger. Lynch is consistently described as a "legend" by the financial media for his performance record. Base on his career I have compiled his investing rules here. 25 GOLDEN RULES by @Peter Lynch 1: Nobody can predict interest rates, the future direction of the economy or the stock market. Dismiss all such forecasts & concentrate on what's actual...
3 comments
Read more

What is version checking in Hibernate ?

Version checking used in hibernate when more then one thread trying to access same data. For example : User A edit the row of the TABLE for update ( In the User Interface changing data This is user thinking time) and in the same time User B edit the same record for update and click the update. Then User A click the Update and update done. Change made by user B is gone. In hibernate you can prevent slate object updation using version checking. Check the version of the row when you are updating the row. Get the version of the row when you are fetching the row of the TABLE for update. On the time of updation just fetch the version number and match with your version number (on the time of fetching).
4 comments
Read more

What is wrong with HDFC securities? Are they doing some fraudulent activities or just causing issues with their platform as usually it don't work during market hours?

I have opened a DEMAT account with HDFC Securities in 2019 as HDFC group is well known for the customer services and I also hold a salary account with HDFC Bank, DEMAT account with the following conditions/offers as expressed by the executive. Trading Account Opening Charges (One Time) :  ₹999 (At that time it offered on lower price, I forget the exact price) Trading Annual Maintenance Charges AMC (Yearly Fee) : ₹0 Demat Account Opening Charges (One Time) : ₹0 Demat Account Annual Maintenance Charges AMC (Yearly Fee) : ₹750, nil if portfolio value below ₹2 lacs. Equity Delivery : 0.50% Equity Intraday : 0.05% Equity Futures : 0.05% Equity Options : ₹100 per lot or 1% of the premium (whichever is higher) Currency Futures : ₹23 per contract Currency Options : ₹20 per contract Commodity Futures : 0.02% for Intraday / 0.025% for positional Commodity Options : 0.02% for Intraday / 0.025% for positional It was going good but after 2-3 months I got to know that there are...
2 comments
Read more

Fundamental Analysis : Asian Paints Ltd.

Asian Paints group is the largest paint manufacturer in India also engaged in the business of manufacturing of varnishes, enamels or lacquers, surfacing preparation, organic composite solvents and thinners. It operates in 15 countries and has 26 paint manufacturing facilities in the world serving consumers in over 60 countries. Besides Asian Paints, the group operates around the world through its various brands viz. Asian Paints Berger, Apco Coatings, SCIB Paints, Taubmans, Causeway Paints and Kadisco Asian Paints. It also manufactures metal sanitary ware such as bath, sinks, washbasins and similar articles. Recently introduced Lightings, Furnishings and Furniture thus adding more products in the Home décor and Interior Design category. Market Cap ₹ 244,763 Cr. Current Price ₹ 2,552 High / Low ₹ 2,873 / 1,483 Stock P/E 89.0 Book Value ₹ 115 Dividend Yield 0.47 % ROCE 33.8 % ROE 27.5 % Face Value ₹ 1.00 Price to book value 22.2 EPS ₹ 28.7 High price all time ₹ 2,873 Low price all time ₹...
10 comments
Read more

What are JEE Containers? What are their different types?

Containers are the interface between a component and the low-level, platform-specific functionality that supports the component. Before it can be executed, a web, enterprise bean, or application client component must be assembled into a Java EE module and deployed into its container. The assembly process involves specifying container settings for each component in the Java EE application and for the Java EE application itself. Container settings customize the underlying support provided by the Java EE server, including such services as security, transaction management, Java Naming and Directory Interface (JNDI) API lookups, and remote connectivity. Here are some of the highlights. The Java EE security model lets you configure a web component or enterprise bean so that system resources are accessed only by authorized users. The Java EE transaction model lets you specify relationships among methods that make up a single transaction so that all methods in one transaction are treated as a ...
4 comments
Read more