SQL is a standard database language used to access and manipulate data in databases. SQL stands for Structured Query Language. SQL 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.
In this SQL tutorial, you’ll learn all the basic to advanced 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.
Table of Content
- What is a Database?
- SQL Basics
- Create Database in SQL
- Tables in SQL
- SQL Queries
- SQL Clauses
- SQL Operators
- SQL Aggregate Functions
- SQL Data Constraints
- SQL Joining Data
- SQL Functions
- SQL Views
- SQL Indexes
- SQL Miscellaneous Topics
- Why to learn SQL?
- Applications of SQL
- Pre-requisites to learn SQL
- SQL Online Quiz
- SQL Jobs and Opportunities
- Advantages of SQL
- Quick Links:
What is a Database?
Before taking a deep dive into this free SQL tutorial let’s understand what is database?
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 the 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 Basics
- What is a Database
- Types of Databases
- What is DBMS
- Relational and Non Relational Databases
- What is SQL?
- SQL Data Types
- SQL Operators
- SQL Commands
Create Database in SQL
Tables in SQL
- SQL CREATE TABLE
- SQL DROP TABLE
- SQL DELETE TABLE
- SQL RENAME TABLE
- SQL TRUNCATE TABLE
- SQL COPY TABLE
- SQL TEMP TABLE
- SQL ALTER TABLE
SQL Queries
- SQL SELECT Statement
- SQL SELECT TOP
- SQL SELECT FIRST
- SQL SELECT LAST
- SQL SELECT RANDOM
- SQL SELECT IN
- SQL SELECT Multiple
- SQL SELECT DATE
- SQL INSERT Multiple Rows
- SQL INSERT INTO
- SQL UPDATE Statement
- SQL DELETE Statement
- SQL DELETE Duplicate Rows
SQL Clauses
- SQL WHERE Clause
- SQL WITH Clause
- SQL HAVING Clause
- SQL ORDER By Clause
- SQL Group By Clause
- SQL LIMIT Clause
SQL Operators
- SQL AND Operator
- SQL OR Operator
- SQL LIKE Operator
- SQL IN Operator
- SQL NOT Operator
- SQL NOT EQUAL Operator
- SQL IS NULL Operator
- SQL UNION Operator
- SQL UNION ALL Operator
- SQL EXCEPT Operator
- SQL BETWEEN Operator
- SQL ALL Operator
- SQL ANY Operator
- SQL INTERSECT Operator
- SQL EXISTS Operator
- SQL CASE Operator
SQL Aggregate Functions
- SQL Aggregate Function
- SQL Count() Function
- SQL SUM() Function
- SQL MIN() Function
- SQL MAX() Function
- SQL AVG() Function
SQL Data Constraints
- SQL NOT NULL Constraints
- SQL UNIQUE Constraints
- SQL Primary Key Constraints
- SQL Foreign Key Constraints
- SQL Composite Key
- SQL Unique Constraints
- SQL Alternate Key
- SQL CHECK Constraints
- SQL DEFAULT Constraints
SQL Joining Data
- SQL JOIN
- SQL Outer Join
- SQL Left Join
- SQL Right Join
- SQL Full Join
- SQL Cross Join
- SQL Self Join
- SQL UPDATE with JOIN
- SQL DELETE JOIN
- SQL Recursive Join
SQL Functions
- Date Functions in SQL
- String Functions in SQL
- Numeric Functions in SQL
- Statistical Functions in SQL
- JSON Functions in SQL
- Conversion Functions in SQL
- Datatype Functions in SQL
- LTRIM Function in SQL
- UPPER Function in SQL
- RTRIM Function in SQL
SQL Views
- SQL CREATE VIEW
- SQL DROP VIEW
- SQL UPDATE VIEW
- SQL RENAME VIEW
- SQL DELETE VIEW
SQL Indexes
- SQL Indexes
- SQL Create Index
- SQL Drop Index
- SQL Show Indexes
- SQL Unique Index
- SQL Clustered Index vs Non-Clustered Index
SQL Miscellaneous Topics
- SQL Wildcards Operators
- SQL Comments
- SQL Pivot and Unpivot
- SQL Injection
- SQL Hosting
- SQL Performance Tuning
- SQL Stored Procedures
- SQL Transactions
- SQL Sub Queries
- SQL Using Sequences
- SQL Auto Increment
- SQL Window functions
- SQL Date & Time
- SQL Cursors
- SQL Common Table Expressions
- SQL Database Tuning
- SQL Dynamic SQL
Why to learn SQL?
SQL helps you to easily get information from data at 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 ANSI and ISO standard language for database manipulations.
- SQL retrieves large amounts of data very fast.
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 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.
Pre-requisites to learn SQL
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 Online Quiz
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 to 65,000 INR. In this section, we have listed some of the top giant companies that hire SQL experts.
- Microsoft
- Amazon
- Meta
- Apple
- Accenture
- Deloitte
- McKinsey & Company
- Boston Consulting Group
- KPMG
- JPMorgan Chase
- Bank of America
- Citigroup
- Wells Fargo
- HSBC
- Netflix
- Airbnb
- Capgemini
- Wipro
- Infosys
- Tata Consultancy
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.
Quick Links:
- SQL | Subjective Problems
- SQL | Multiple Choice Questions
- SQL | Interview Questions
- SQL Interview Questions | Set 1
- SQL Interview Questions | Set 2
- SQL | Commonly asked DBMS interview questions | Set 1
- SQL | Commonly asked DBMS interview questions | Set 2
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.
If you’re looking out 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.