SQL Courses

Approved by the International Standard Organization and American National Standard Institute, SQL aims to provide the following features:

1. DDL - Data Definition Language:

SQL provides many commands, one of which is DDL. Also referred to as the Data Description Language, it includes the commands used to define the data. This particular command contains within itself five more commands:

i) Create Command: It is used if the programmer wants to create a table.

Syntax: Create table table_name

          {

            Column_1 datatype;

            Column_2 datatype;

            …

            Column_n datatype;

          };

ii)   Drop Command: If the programmer wants to delete the table inclusive of the contents of the table, then this command is used

Syntax: droptable table_name;

iii) Alter Command: If a programmer wants to alter the table's contents, such as adding or deleting the columns or rows, this command is used.

Syntax: altertable table_name

           {

             Add new_column_1 datatype;

             Add new_column_2 datatype;

           }

iv) Rename Command: When the programmer wants to change or alter the table's name, this command is used.

Syntax: renametable old table_name;

To new_table_name;

v) Truncate: When the programmer wants to delete the table contents without affecting the table structure, this command is used.

Syntax: Truncate table table_name;

2. DML – Data Manipulation Language:

After receiving raw data, the data must be supervised and manipulated into tables with proper structure. This is done by DML. The following commands are used to manipulate the data:

i) Insert Command: When the programmers want to insert a set of values into the table's structure, this command is used.

Syntax: Insert into table_name(column_1_name, column_2_name,…) values(value_1, value_2..)

ii) Select Command: When the programmer wants to select a piece of information from the structure of the table, then this command is utilized. It is one of the essential commands in SQL. However, there are many formats depending on the requirement type. Everyone should note that while using this command, the table contents must be full and not empty.

The syntax for displaying the information in the table:

Select * table_name;

iii) Update Command: When the programmer wants to update some information into an existing table, then this command is used

Syntax: Update table_name set;

Column_name1=value1, Column2_name1=value2;

  . . . . .

  Where condition();

iv) Delete Command: This command is used when the programmer wants to delete any content from the table or data from the table.

Syntax: Delete from table_name where condition;

3. Efficient Performance: As the data is being generated in a large number, manipulated using simple commands of Data Manipulation Language and Data Description Language, easy operations can be performed on them. Using SQL, queried data return vast sets of data very quickly. In most successful organizations, the people work on making optimal query plans for efficient and quick data manipulations.

4. Client-Server Interaction: The recent trend of client-server technology permits building relationships with many clients on one server. SQL offers commands that allow the client to access the database over a network using a simple application.

5. Authentication and Security: SQL approves authentication to users using credentials like usernames and passwords. It also assures that the required data is shown to the user while the original and authorized data is stored in a database management system.

Various studies are going on to work with data and determine their insights and knowledge. SQL queries are a hot topic in Data Science, Artificial Intelligence, and Machine Learning. Companies are paying a large amount to data science engineers and analysts to infer information from the data. Their role is to assure the company of their assets and enable the data the organizations require if the need arises. However, the common uses of SQL are as follows:

• Banking Systems, and stores, i.e., the finance industry, require SQL to back them up for data operation to carry out smooth transactions. However, extra security measures are necessary for banking systems as hacking is a security threat. This requires advanced SQL developers with experience in ethical hacking added with a hint of SQL language knowledge.

• Applications and Websites require SQL as there are databases that require the expertise of management. SQL developers usually perform operations on data to understand the users' needs of the applications and websites and what they are looking for.

• Digital marketing requires SQL. It involves data processing. Even Social Media Platforms such as Facebook, Instagram, and Twitter require the users to fill in their basic details such as name, email, profession, location, etc. SQL performs all these operations.

• Analyzes a huge amount of data to draw necessary insights to support business objectives.

• Optimizes and supervises databases.

• Ensures the storage, organization, and easy retrieval of data.

• Maybe involved directly or indirectly in managing the databases.

• Examines raw data to find errors and bugs in the software by performing operations like inserting queries in SQL and reporting the observations and changes

People interested in knowing how the applications work at their fingertips require a basic understanding of SQL. Learning SQL will only hone your skills as a developer and provide you with a knowledge of applications and their backend frame.

One can view in SQL many commands that can be utilized to build an application. It will help you manage the data and get noticed by large organizations that will expand your career. Apart from the basic understanding of SQL, one must realize that there is no requirement of writing thousands of lines of code or knowledge. It is easy to learn.

Apart from the Data Scientist interested in Artificial Intelligence, Machine learning, etc., the following are the ones who use SQL:

Stored in the relational database is the data procured and managed using SQL. Thus, SQL has become the common language in managing and performing operations on the data. Usually, data analysis is done on another platform such as Python, Java, etc. But to analyze the data, fetch the data, and organize the data to perform the complete streamlining is mainly done by SQL.

Numerous platforms represent various frameworks and versions of SQL. The most commonly used across the globe is MySQL. MySQL happens to be one of the open-source platforms that help facilitate the role of SQL in managing and supervising the backend data to develop a wide variety of web applications. SQL performs Back-end Data Processing, Data Analyzing, and data storage. This is why huge companies such as Instagram, Facebook, and WhatsApp use SQL as their primary tool. No SQL tools require extensive coding.

Query Optimizer is the term referred to as the processing of an SQL query written and executed. When the query is executed, it reaches the SQL Server. Once it reaches the SQL server, it performs the following functions:

• Parsing: The process of checking the syntax after writing an SQL query

• Binding: The process of reviewing the semantics of a query

• Optimization: The process of generating the plan of query execution

The optimization process performs many permutations and combinations that generate the query execution plan in real-time. When a query takes a shorter time, the better the query is. Thus SQL can be used with a basic understanding and knowledge of databases, tables, and procedures.

SQL is used in applications where the framework can be created only by SQL. This brings us to the subject of what can SQL do, and the following is the list:

If a person is already working with relational databases, it is a fundamental need. However, there is no right time to learn SQL. But when planning a career in data science, artificial intelligence, or machine learning, where working and managing the raw data is the leading role, SQL is a basic essential. 

As SQL is a scripted language, it is easier to learn than other programming languages such as C, C++, Python, and Java. This means that anyone can gain mastery over the art of SQL within a few weeks, given constant dedication, practice, and learning.

As discussed before, SQL is a very easy language to learn. But depending on the designation, it gets harder with higher roles and responsibilities. The estimated time to learn SQL is two to three weeks. SQL is a programming language with comprehensible syntax, queries, data formats, commands, and concepts of tables. Once a person is familiar with the syntax, queries, and commands, anyone can earn SQL understanding. SQL by upGrad is an online certification that aims to provide a complete knowledge of SQL.

Besides organizing, managing, and storing vast amounts of data, using SQL and its server, you can do the following things:

There are mainly five topics that include various commands:

1. DDL: Data Definition Language

i) Create Command: If the programmer wants to create a table, this command is used.

Syntax: Create table table_name

          {

            Column_1 datatype;

            Column_2 datatype;

            …

            Column_n datatype;

          };

ii)   Drop Command: If the programmer wants to delete the table inclusive of the contents of the table, then this command is used

Syntax: droptable table_name;

iii)   Alter Command: If a programmer wants to alter the contents of the table such as adding or deleting the columns or rows, this command is used.

Syntax: altertable table_name

           {

             Add new_column_1 datatype;

             Add new_column_2 datatype;

           }

iv)   Rename Command: When the programmer wants to change or alter the table's name, this command is used.

Syntax: renametable old table_name;

           To new_table_name;

v)     Truncate: When the programmer wants to delete the table contents without affecting the table structure, this command is used.

Syntax: Truncate table table_name;

2. DML: Data Manipulation Language

 i) Insert Command: When the programmers want to insert a set of values into the table's structure, this command is used.

Syntax: Insert into table_name(column_1_name, column_2_name,…) values(value_1, value_2..)

ii)Select Command: When the programmer wants to select a piece of information from the structure of the table, then this command is utilized. It is one of the essential commands in SQL. However, there are many formats depending on the requirement type. Everyone should note that while using this command, the table contents must be full and not empty.

The syntax for displaying the information in the table:

Select * table_name;

iii)Update Command: When the programmer wants to update some information into an existing table, then this command is used

Syntax: Update table_name set;

Column_name1=value1, Column2_name1=value2;

 . . . . .

 Where condition;

iv) Delete Command: This command is used when the programmer wants to delete any content from the table or data from the table.

Syntax: Delete from table_name where condition;

3. DCL – Data Control Language:

When the programmer wants to grant or withdraw access or authorization from any database user, these commands are used. There are two commands:

i) Grant Command: When a programmer wants to provide access to a database user, this command is used.

Syntax: Grant Select, Update on my_table to user_1, user_2;

ii) Revoke Command: This command is used whenever a programmer wants to withdraw access from the user.

Syntax: Revoke Select, Update on my_table to user_1, user_2;

4. TCL – Transactional Control Language:

These are the commands that are already present in the database. This is why they are always used only with DML Commands such as Insert, delete, and update commands.

i)   Commit Command: It saves all the transactions in the database.

ii)   Rollback Command: This command is used to revert the transactions that are not saved in the database.

iii) Save point Command: Without rolling back to the entire transaction, this command is used to roll back to a specific transaction only.

5. DCL - Data Query Language:

It is only used to retrieve the data from the databases.

i) Select Command: This command selects the attribute depending on the condition defined by the ‘where’ clause.

Here are some of the essential statements and functions of SQL.

Select Statement

Select Statement is used to select the data from the database. Data returned is stored in the result table called the result set.

The syntax for displaying the information in the table:

Select * table_name;

Joining Tables

The SQL join clause combines records from two or more tables in a database.

ANSI standard SQL defines five types of joins:

i) Inner Join: This inner join keyword is responsible for selecting the records with similar values in both the preset tables.

Syntax: SELECT Colum_name (s)

FROM table1
Inner join table2

ON table column_name = table2 column_name2

ii) Left Join: The left join keyword returns all records from the left table(table1), and the matching records from the right table (table2). The result is the record from the right side if it does not  matches.

Syntax: SELECT Column_name(s)

           From table1

           Left join table2

           On table column_name=table2 column_name2;

iii) Right Join: The right join keyword returns all records from the right table(table2) and the matching records from the left table(table1). The result is a record from the left side if it does not match.

Syntax: SELECT Column_name(s)

           From table1

           Right join table2

           On table column_name=table2 column_name2;

iv) Full Join: This full outer join  is a keyword that returns all records only when there is a match in left (table1) or right (table2) records of the table.

Syntax: SELECT Column_name(s)

           From table1

           Full Join join table2

           On table column_name=table2 column_name2;

Filtering of Data: Data filtering includes the text strings used to specify the subsets in the records.

• Where Clause: It filters records and extracts only those records that fulfill a specific condition.

Syntax: SELECT Column1, Column2,….

          From Table_main

          WHERE condition;

SQL comments are used to add notes to the code.

• Logical Operators:

And Operator: The AND operator displays a record if all the conditions are separated by AND are true.

Or Operator: The OR operator displays a record if any of the conditions are separated by OR is true.

NOT Operator: The NOT operator displays a record if the condition(s) is not True

In Operator: This operator can declare many values in a WHERE Clause. it is a shorthand for multiple OR conditions.

SQL between operator: This BETWEEN SQL operator chooses a value in a specified range. The number can be Dates or Texts. The BETWEEN operator is inclusive of starting & ending values.

Like Operator: It is used in a WHERE clause to identify a particular pattern in a column. Two wild cards are often used with the LIKE operator.

Creating Calculated Fields: This is used to create new data from the existing raw data. It is done by adding additional logic to the database.

Syntax:

CREATE TABLE t1(

col1 int,

col2 int,

col3 int,

col4 as (col1*col2*col3)/ 

)

insert into t1  values(1,2,3)

 select * from t1

 Summarizing Data: Based on specific criteria that have been defined previously, summary functions are used to summarize the data by a set of expressions. A summary of the data is done as it represents the review of large datasets. This permits the analysts to analyze the data very quickly and efficiently. It also makes the process quicker.

Working with dates and times: With mathematical expressions and logic, date and time values can be manipulated in SQL. The only two prerequisites are the value that needs manipulation and a mathematical operator to manipulate.

Every subject has its pros and cons. Same way, SQL has both advantages and disadvantages.

The advantages of SQL are as follows:

• Easy to learn: SQL is a language that is easy to learn as it has simple syntax, queries, and commands.

• No coding skills required: SQL does not demand knowledge of programming languages such as Python, C, C++, Java, etc.

• Quick Query Processing: Manipulating, organizing, and analyzing the data is done within seconds of retrieving a large volume of data using SQL

• Highly Interactive: For people who do not understand programming well, SQL is a very interactive language to learn. It is easily understandable by all.

• Portable: It is efficiently portable for all laptops with any operating system from Windows to Linux. It also provides the option of embedding into the applications.

• Open-Source: As it is an open-source platform, it can be easily used by any user sitting anywhere in the world.

Relational Databases refer to the storage of data in tabular form. In tabular form, the columns that store the assets and the rows in the table store a record. Here are the common relational databases used by large companies and organizations to start-ups and businesses:

·       MySQL: It is a popular open-source relational database. While working in embedded systems and client-server communication, it is scalable, portable, and has a quick response.

·       SQL Server: Developed by Microsoft, the SQL Server is a popular relational database among major companies. Some of the editions of the SQL Server are

1. SQL Server Enterprise Edition
2. SQL Server Developer Edition
3. Azure SQL Database
4. SQL Compact Edition
   
   

·     Oracle: Oracle is developed by Oracle Corporations. It is not only the most used relational database but also provides other features such as Graph Database Management System, Cloud Storage, Document Storage, PDF Storage, Blog, and Key-value storage.

As we know the fundamental concept of SQL and MySQL, let’s dive into the difference between SQL and MySQL:

While SQL is a query programming language that manages relational databases, MySQL is a relational database that uses SQL. SQL is used to retrieve, organize and manipulate the data from the databases using SQL commands. Where MySQL is used to store the data in the databases using SQL.

MySQL has the support of connectors as it has in-built MySQL work benches. SQL does not involve the support of connectors.

When it comes to the security of the data, SQL is more secure than MySQL. In MySQL, anybody can modify and manipulate the data. SQL is a standard language, while MySQL is an open-source platform and is easy to use.

MySQL can be downloaded for free as a standalone installer. There are different links for installing MySQL on different operating systems.Click here to install MySQL for free.

SQL courses are better than offline SQL courses because of the resources and flexibility. The students can access the course materials and resources whenever it is required. They can learn at their own convenient pace, which removes the additional pressure. It also allows the students to choose from different courses depending on their interests. 

You can learning SQL on online platforms that do not require students to be physically present in the class. As the material for learning SQL is present online, it becomes easier for the students to access it at any time. Also, if you pursue online courses from top online institutes like upGrad, you get valuable certifications to enhance your resume.

The syllabus covers the following:

The SQL industry is expected to grow by an average of 7.6% annually from 2022-to 23. This growth will be driven by continued demand for data-driven insights and the evolution of SQL-based technologies.

SQL can help businesses streamline their processes in several ways. By allowing companies to store and retrieve data more efficiently, SQL can help reduce the time and resources required to manage information. In addition, SQL can help businesses automate tasks such as data entry and reporting, which can further improve efficiency. Finally, SQL can provide businesses with powerful tools for analyzing and understanding their data, which can help them make better decisions about their operations.

The demand for learning SQL to manipulate the large volume of data generated has increased over the past few years. 

Learn SQL on the following platforms:

• PG Diploma in Software Development (Specialization in Cloud Computing) with IIIT Bangalore - upGrad 

• SQL Fundamentals – DataQuest

• Complete Oracle SQL Certification Course – Udemy

• Complete SQL Mastery – CodewithMosh

• Postgre SQL for Everybody – Coursera

• The Ultimate MySQL Bootcamp – Udemy

An SQL Developer base salary in India is INR 5 LPA – INR 6 LPA. However, the range lies between INR 2 LPA – INR 11 LPA.

Factors on which SQL Specialist Salary in India Depends on

The factors on which the SQL Specialist Salary in India Depends are - 

• Experience
• Location
• Company Requirements
• Communication Skills
• Proficiency in SQL
• Good understanding of data structures and algorithms
• Knowledge of Various operating systems
• Analytic and Problem-Solving Skills
• Team Leader and Teamwork
• Knowledge of relational database management systems

SQL Specialist Starting Salary in India

The average starting salary of a specialist in India is 5LPA – 12LPA, depending on the above factors.

Here are some of the references to the SQL specialist salary abroad. 

• In the United States, a SQL Specialist can expect to make an average annual income of $90,668.
• In Ukraine, a SQL Specialist makes an average annual income of $71,560.
• In Australia, a SQL Specialist makes an average annual pay of $71,950.
• In Germany, a SQL Specialist receives an estimated annual pay of $59,160.

Factors on which SQL Specialist Abroad Salary Depends

The following are the variables that affect the SQL Specialist Salary Abroad:

• Experience
• Company Requirements 
• Location or Area of Work
• Skills in Communication
• Knowledge of SQL
• Sufficient experience with data structures and algorithms
• Understanding operating systems
• Skills in Analysis and Problem-Solving
• Teamwork as well as the Team Leader
• The capability to use relational database management systems
• Solid Mathematical Background

SQL Specialist Starting Salary Abroad

The starting salary of an SQL Specialist abroad might range from $48,000 - $60,000. However, it might also depend on a few factors. It mainly reflects on the experiences and location of work, remote or in-office.