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 learn 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.
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:
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.
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 TutorialSQL 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.