Skip to main content

SQL Overview

Hello and welcome all to a new series to understand the SQL statements in simpler ways. In this series we will try to learn about Data, Database and SQL statements along with their syntax, execution and examples. Before understanding commands of SQL, we have to learn some basics about SQL. And before we learn about a SQL, let us understand what SQL is used for.

What is Data?
In simple words, data can be a piece or collection of information or we can also say that data is 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?
A database is a systematic collection of data. They support electronic storage and manipulation of data. Databases make data management easy.

Let us discuss a database example: An online telephone directory uses a database to store data of people, phone numbers, and other contact details. Your electricity service provider uses a database to manage billing, client-related issues, handle fault data, etc.

Let us also consider Facebook. It needs to store, manipulate, and present data related to members, their friends, member activities, messages, advertisements, and a lot more. We can provide a countless number of examples for the usage of databases.

Now, to access, manage or modify the data in the database, we need a medium or a language to make database understand our requirement, that medium or language is SQL.

What is SQL?
SQL stands for Structured Query Language. SQL is used to create, remove, alter the database and database objects in a database management system and to store, retrieve, update the data in a database. SQL is a standard language for creating, accessing, manipulating database management system. SQL works for all modern relational database management systems, like SQL Server, Oracle, MySQL, etc.Data is stored in the form of tables in sql. And table is divided into several columns according to requirement.So now that we have understand the SQL and its use, let’s move ahead to know about types of SQL statements.

Types of SQL Commands
SQL commands can be categorized into five categories based on their functionality and uses.

1. Data Definition Language (DDL)
DDL commands are used for creating and altering the database and database object in the relational database management system, like CREATE DATABASE, CREATE TABLE, ALTER TABLE, etc. The most used DDL commands are CREATE, DROP, ALTER, and TRUNCATE.

2. Data Manipulation Language (DML)
DML commands are used for manipulating data in a relational database management system. DML commands are used for adding, removing, updating data in the database system, like INSERT INTO TableName, DELETE FROM TableName, UPDATE tableName set data, etc. The most used DML commands are INSERT INTO, DELETE FROM, UPDATE.

3. Data Query Language(DQL)
DQL command is used for fetching the data. DQL command is used for selecting data from the table, view, temp table, table variable, etc. There is only one command under DQL which is the SELECT command.

4.Data Control Language(DCL)
DCL stands for data control language. DCL commands are used for providing and taking back the access rights on the database and database objects. DCL command used for controlling user’s access on the data. Most used DCL commands are GRANT and REVOKE.

5.Transaction Control Language(TCL)
TCL commands are used for handling transactions in the database. Transactions ensure data integrity in the multi-user environment. TCL commands can rollback and commit data modification in the database. The most used TCL commands are COMMIT, ROLLBACK, SAVEPOINT, and SET TRANSACTION.

So, here we come to the end of the first part of the SQL series blog in which we understood what is Data, Database, SQL, why SQL is required and what are different types of SQL commands. I hope you liked it and stay tuned for another series where in we will explore more about the different types of SQL commands.

About Amlgo Labs : Amlgo Labs is an advanced data analytics and decision sciences company based out in Gurgaon and Bangalore, India. We help our clients in different areas of data solutions includes design/development of end to end solutions (Cloud, Big Data, UI/UX, Data Engineering, Advanced Analytics and Data Sciences) with a focus on improving businesses and providing insights to make intelligent data-driven decisions across verticals. We have another vertical of business that we call - Financial Regulatory Reporting for (MASAPRAHKMAEBAFEDRBI etc) all major regulators in the world and our team is specialized in commonly used regulatory tools across the globe (AxiomSL Controller ViewOneSumX DevelopmentMoody’s RiskIBM Open Pages etc).We build innovative concepts and then solutions to give an extra edge to the business outcomes and help to visualize and execute effective decision strategies. We are among top 10 Data Analytics Start-ups in India, 2019 and 2020.

Please feel free to comment or share your views and thoughts. You can always reach out to us by sending an email at info@amlgolabs.com
 or filling a contact form at the end of the page.

Comments

More Popular Posts

Amlgo Blog - Experience The Experiments

Amlgo Labs Blog  is a step towards our vision to share knowledge and experiences, Amlgoites accept every challenge very enthusiastically. We do experiments, we fail but we learn and build complex solutions to help our clients solve their problems in Data, Analytics, Prediction, Forecasting, Reporting, Designing and Development area. During this process we enjoy immense learning everyday and we have decided to share our thoughts, learnings, experiments and experiences so that we don't work in silos and contribute the best of our knowledge towards community and learn more by views and reviews. This website is maintained and brough to you by  Amlgo Labs Professionals .   Our Strong Basics -  1)   KISS (Keep It Simple and Straightforward) :  We believe most of the problems can be solved by keeping things simple and straight. This is the learning we had in past, sometimes we try to solve technical problems using high end algorithms and complex codes but this results into complications.

Power BI Blog - What is Power BI and Why we use Power BI.

This Power BI blog is an introduction to the Power BI. In this Power BI tutorial, you will learn Power BI basics - what is Power BI, Power BI Desktop and Power BI Service. Power BI tool is a combination of Business Intelligence and Visualization. Before we dig deep let’s understand what is Business Intelligence. Business Intelligence is a broad spectrum which consists of using different business strategies and techniques to gather data, refine it and process it for the purpose of data analysis which gives us some meaningful information which helps in data driven decision making. When we present this information in the form of some charts, graphs it takes the form of Visualization.

Power BI Card Visual With Conditional Formatting

In this blog we will take you through the Power BI Card Visual and a workaround to present card with conditional formatting. To know more about what is Power BI please do check Power BI Blog . The conditional formatting, we do will not be on the Card Visual, but the output will certainly look like Card, which is a requirement in some cases. Many Power BI users have used Card Visual to represent some value on the Power BI Reports separately or on above of any other visual, but sometimes clients ask which is deemed difficult to achieve, but not impossible. So, let’s dive into the practical to know more about it.

A simplified view of a QlikView tool:

In our last blog related to Qlikview, we discussed the use of Qlikview for Financial Data Analytics . Qlikview is a Business Intelligence tool that consists of a front end to visualize the processed data and a back end to provide the security and publication of the mechanism for QlikView user documents.

Polybase Installation for Scale-Out process

This part is the continuation of the previous blog about the introduction of  Polybase Scale-Out Group . As we have discussed in our earlier blog PolyBase enables your SQL Server instance to process Transact-SQL queries that read data from external data sources. SQL Server 2016 and higher can access external data in Hadoop and Azure Blob Storage. Starting in SQL Server 2019, PolyBase can be used to access external data in SQL Server, Oracle, Teradata, and MongoDB.

JavaScript: The Important Basics

In this weird world of technology people often get confused how does a website work? What all things should I be aware of? So we are here to help you. Most of the content on web is developed with the help of JavaScript. JavaScript is really becoming popular these days with the coming of ECMAScript2015 and ECMAScript 2016, for this reason, some beginners learning React and Angular and are also trying to tackle more modern JavaScript syntax at the same time. If you're new to both, it can be confusing as to "what is JavaScript and what are its important features". This document should serve as a primer to help you get up-to-speed on JavaScript syntax that we feel matters the most for learning React as well as Angular.

How to Connect Windows with Ansible?

Hello Techies, this blog is the continuation of the last blog Install Ansible on Windows which is the second part of the series Ansible with Windows . Before you proceed, I recommend you to please take a look at the introductory blog of this series so to have an understanding of this series.