Open In App

SQL Tutorial

Last Updated : 06 May, 2024
Improve
Improve
Like Article
Like
Save
Share
Report

In this SQL tutorial, you’ll learn all the basic to advanced SQL concepts like SQL queries, SQL join, SQL injection, SQL insert, and creating tables in SQL. SQL is easy to learn, there are no prerequisites to learning SQL.

So, SQL is a standard database language used to access and manipulate data in databases. SQL stands for Structured Query Language. It was developed by IBM Computer Scientists in the 1970s. By executing queries SQL can create, update, delete, and retrieve data in databases like MySQL, Oracle, PostgreSQL, etc. Overall, SQL is a query language that communicates with databases.

What is a Database?

Before deep diving into this free SQL tutorial, let’s understand what a database is.

So, data is the new fuel of this world, but data is unorganized information, so to organize that data, we make a database. A database is an organized collection of structured data, usually controlled by a database management system (DBMS). Databases help us easily store, access, and manipulate data held on a computer.

SQL Example

In this detailed SQL tutorial for beginners, we’ll explore practical SQL examples for managing employee data within a database. We’ll create a table to store employee information and populate it with sample data like Employee_Id, Name, Age, Department, and Salary.
Employee_Table

If you want to retrieves data from the employees table where the salary is greater than 55000.00 then we will use SELECT Statement.

Query:

SELECT * FROM employees WHERE Salary > 55000.00;

Output:

Employee_output

Explanation:

This SELECT statement retrieves records from the employees table where the Salary column is greater than 55000.00. The * symbol indicates that we want to retrieve all columns for the matching records. The WHERE clause filters the results based on the specified condition.

Why to Learn SQL?

SQL helps you to easily get information from data with high efficiency. To manipulate the data in databases like Create, Read, Edit, and Delete, we use SQL queries. Users can interact with data stored in relational database management systems. Anyone who knows the English language can easily write SQL queries. Some of the key features of SQL are given below:

  • Without a lot of coding knowledge, we can manage a database with SQL.
  • SQL works with database systems from Oracle, IBM, Microsoft, etc.
  • Simple and easy to learn.
  • SQL is an ANSI and ISO standard language for database manipulation.
  • SQL retrieves large amounts of data very fast.

Pre-Requisites to Learn SQL

If you want to learn SQL then, this free SQL tutorial is quite easy to understand because, during the development of this course, we tried our best to provide the best resource to clear your SQL concept.

But we assume that you are already aware of the basic conceptions of computer science, like databases and its types.

So, if you have basic knowledge of RDBMS, then this SQL tutorial provides you with enough knowledge to master SQL.

Learn-SQL

SQL Basics

SQL or Structure Query Language is a fundamental skill for anyone who wants to interact with databases. This standard Query Language all users to create, manage, and retrieve data from relational databases. In this SQL tutorial PDF, we have listed all the basics of SQL. Explore this section to sharpen your SQL basics.

Explore More Recent Articles’ on SQL

Create Database in SQL

The first step to storing the information electronically using SQL includes creating database. And in this section we will learn how to Create, Select, Drop, and Rename databases with examples.

Tables in SQL

The cornerstone of any SQL database is the table. Basically, these structure functions is very similar to spreadsheets, which store data in very organized grid format. In this section, you will learn how to Create, Drop, Delete, and more related to Table.

SQL Queries

In this section, you will learn about the SQL Queries like SELECT statement, SELECT LAST, and more. Explore this section and learn how to use these queries.

SQL Clauses

Unlock the power of SQL Clauses with this SQL tutorial. Here in this section, you will learn how to use SELECT, WHERE, JOIN, GROUP BY, and more to query databases effectively.

SQL Operators

SQL Operators” refers to the fundamental symbols and keywords within the SQL that enable users to perform various operations and SQL AND, OR, LIKE, NOT, and more operators on databases. Here, we have discussed all the SQL operators in a detailed manner with examples.

SQL Aggregate Functions

Whether you are calculating the total sales revenue for a particular product, finding the average age of customers, or determining the highest value in a dataset, SQL Aggregate Functions make these tasks straightforward and manageable.

SQL Data Constraints

Constraints act as rules or conditions imposed on the data, dictating what values are permissible and what actions can be taken. They play a crucial role in maintaining the quality and coherence of the database by preventing errors. So, explore this section to get a hand on SQL Data Constraints.

SQL Joining Data

SQL joins serve as the weaver’s tool, allowing you to seamlessly merge data from multiple tables based on common threads. So explore this section to learn how to use JOIN command.

SQL Functions

SQL functions offer an efficient and versatile approach to data analysis. By leveraging these functions within your queries, you can enhance the depth and accuracy of your insights, transforming raw data into actionable knowledge.

SQL Views

Views makes easier for anyone to access the information they need, without getting bogged down in complicated queries. Views also act like a helpful security guard, keeping the most sensitive information in the back room, while still allowing access to what’s needed.

SQL Indexes

Indexes work by organizing specific columns in a particular order, allowing the database to quickly pinpoint the information you need. And in this section, we have listed all the points that one has to learn while learning SQL.

SQL Miscellaneous Topics

In this miscellaneous section, you will encounter concepts like stored procedures for automating repetitive tasks, triggers for automated actions based on data changes, and window functions for complex calculations within a single query.

SQL Tutorial Important Note

In SQL, keywords are not case-sensitive, meaning “update” is equivalent to “UPDATE“.

SQL Important Commands

Here is the list of some important SQL Commands:

Commands

Descriptions

SELECT

Used to retrieve data from a database.

INSERT

Adds new records or rows to a table.

UPDATE

Modifies existing records in a table.

DELETE

Removes records from a table.

CREATE TABLE

Creates a new table in the database.

ALTER TABLE

Modifies an existing table structure.

DROP TABLE

Deletes a table from the database.

CREATE INDEX

Creates an index on a table column to speed up data retrieval.

DROP INDEX

Removes an index from a table.

CREATE VIEW

Creates a virtual table based on the result of a SQL statement.

DROP VIEW

Deletes a view from the database.

INSERT INTO SELECT

Inserts data from one table into another based on a query.

TRUNCATE TABLE

Removes all records from a table, but keeps the table structure intact.

ALTER TABLE ADD CONSTRAINT

Adds a constraint to a table after it has been created.

GRANT

Gives specific privileges to database users.

REVOKE

Removes specific privileges from database users.

COMMIT

Saves all changes made since the last commit.

ROLLBACK

Discards all changes made since the last commit.

BEGIN TRANSACTION

Starts a new transaction.

SET TRANSACTION

Sets characteristics for the transaction.

Applications of SQL

In data-driven industries where managing databases is very important in regular, Here are some important SQL applications.

  • To support client/server architecture, software engineers use SQL to establish the connection between the back-end and front-end.
  • SQL can also be used in the 3-tier architecture of a client, an application server, and a database.
  • SQL is used as a Data Definition Language(DDL) in which we can independently create a database, define the structure, use it, and discard it when its work is done.
  • SQL is used as a Data Manipulation Language(DML) in which we can enter data, modify data, and extract data.
  • SQL is used as a Data Control Language(DCL) it specifies how we can protect our database against corruption and misuse.
SQL-Tutorial

SQL Tutorial

SQL Online Quiz Test

Start your Online SQL Quiz

SQL Jobs and Opportunities

There are numerous companies around the globe seeking SQL professionals, and they pay high packages. The average salary of SQL developers is around 40,000–65,000 INR. In this section, we have listed some of the top giant companies that hire SQL experts.

Advantages of SQL

SQL or Structured Query Language, is one of the most popular query languages in the field of data science. SQL is the perfect query language that allows data professionals and developers to communicate with their databases.

In the below section, we have listed some of the most prominent advantages or benefits of Structured Query Language:

  • Simple and Easy to Learn: Most of the commands and syntax in SQL are like normal English, which makes SQL easy to learn. Along with this, SQL follows a logical structure that helps promote readability and understanding.
  • Efficiency and Speed Execution: Well, SQL is optimized for RDBMS, which means relational database, and this thing ensures fast query execution.
  • Standardization: SQL is a widely accepted standard query language and ensures compatibility across different database systems.
  • Scalable: SQL can efficiently manage massive datasets, accommodating growth without compromising performance.

Latest Trends and Updates in SQL World

The world of SQL is constantly evolving, so here are some of the hottest trends and updates to keep you in the loop:

Big Data and SQL: Big data store vast amounts of information from various sources. SQL queries act as a bridge, enabling users to extract specific data subsets for further analysis.

Cloud Computing and SQL: Cloud SQL lets your database scale up or down based on your needs. Along with that it very cost effective so you have only pay for the resources you use, making it a cost-efficient option for businesses of all sizes.

Machine Learning and SQL: Data scientists leverage SQL to prepare and clean data for analysis, making it a crucial skill for this field.

Real-time Data Processing with SQL: The need for immediate insights is driving the growth of streaming SQL. This allows you to analyze data as it’s generated, providing real-time visibility into what’s happening.

SQL in Data Governance and Compliance: With stricter data privacy regulations, SQL is playing a role in ensuring data security and compliance. Queries can be used to control access to sensitive information and track data usage for auditing purposes.

Quick Links:

Ending Note

If you’re looking for a worthwhile and reliable SQL tutorial for beginners, (or experts as well), then you must go through with this resource. Also, here you’ll get SQL interview questions, exercises, examples, etc.

Frequently Asked Questions About SQL

1. What are the types of SQL?

There are 5 types of SQL of commands DDL (Data Definition Language), DML (Data Manipulation Language), DCL, (Data Control Language), TCL (Transaction Control Language), DQL (Data Query Language)

2. How do I start learning SQL?

Well, if you want to start learning SQL, then first you have to set your goals, and after that, you have to find the resource from which you can easily learn SQL. After that, you have to do the regular practice to upscale your skills.

3. What are the basic commands of SQL?

The basic commands of SQL are UPDATE, SELECT, INSERT, and DELETE.

4. What are data types in SQL?

SQL has String Data Type, Numeric Data Type, Date and time Data Type.



Similar Reads

Difference between Structured Query Language (SQL) and Transact-SQL (T-SQL)
Structured Query Language (SQL): Structured Query Language (SQL) has a specific design motive for defining, accessing and changement of data. It is considered as non-procedural, In that case the important elements and its results are first specified without taking care of the how they are computed. It is implemented over the database which is drive
2 min read
Configure SQL Jobs in SQL Server using T-SQL
In this article, we will learn how to configure SQL jobs in SQL Server using T-SQL. Also, we will discuss the parameters of SQL jobs in SQL Server using T-SQL in detail. Let's discuss it one by one. Introduction :SQL Server Agent is a component used for database task automation. For Example, If we need to perform index maintenance on Production ser
7 min read
SQL SERVER – Input and Output Parameter For Dynamic SQL
An Input Parameter can influence the subset of rows it returns from a select statement within it. A calling script can get the value of an output parameter. An aggregate function or any computational expression within the stored process can be used to determine the value of the output parameter. A parameter whose value is given into a stored proced
3 min read
Difference between T-SQL and PL-SQL
1. Transact SQL (T-SQL) : T-SQL is an abbreviation for Transact Structure Query Language. It is a product by Microsoft and is an extension of SQL Language which is used to interact with relational databases. It is considered to perform best with Microsoft SQL servers. T-SQL statements are used to perform the transactions to the databases. T-SQL has
3 min read
Difference between SQL and T-SQL
1. Structured Query language (SQL): A structured Query language is a computer language for a relational database system. Relational database system like MySQL oracle Sybase Informix uses SQL as standard database language for storing retrieving manipulating data and store in a relational database. Here are some SQL commands that are used for communi
3 min read
SQL Server | Convert tables in T-SQL into XML
In this, we will focus on how tables will be converted in T-SQL into XML in SQL server. And you will be able to understand how you can convert it with the help of command. Let's discuss it one by one. Overview :XML (Extensible Markup Language) is a markup language similar to HTML which was designed to share information between different platforms.
2 min read
SQL - SELECT from Multiple Tables with MS SQL Server
In SQL we can retrieve data from multiple tables also by using SELECT with multiple tables which actually results in CROSS JOIN of all the tables. The resulting table occurring from CROSS JOIN of two contains all the row combinations of the 2nd table which is a Cartesian product of tables. If we consider table1 contains m rows and table2 contains n
3 min read
How to Execute SQL Server Stored Procedure in SQL Developer?
A stored procedure is a set of (T-SQL ) statements needed in times when we are having the repetitive usage of the same query. When there is a need to use a large query multiple times we can create a stored procedure once and execute the same wherever needed instead of writing the whole query again. In this article let us see how to execute SQL Serv
2 min read
SQL Query to Check if Date is Greater Than Today in SQL
In this article, we will see the SQL query to check if DATE is greater than today's date by comparing date with today's date using the GETDATE() function. This function in SQL Server is used to return the present date and time of the database system in a ‘YYYY-MM-DD hh:mm: ss. mmm’ pattern. Features: This function is used to find the present date a
2 min read
SQL Query to Add a New Column After an Existing Column in SQL
Structured Query Language or SQL is a standard Database language that is used to create, maintain and retrieve data from relational databases like MySQL, Oracle, SQL Server, Postgres, etc. In Microsoft SQL Server, we can change the order of the columns and can add a new column by using ALTER command. ALTER TABLE is used to add, delete/drop or modif
3 min read
Article Tags :