SQL INTRODUCTION

INTRODUCTION:

SQL stands for Structured Query Language.

SQL is the standard database language used to perform operations on the database, such as creating, Manipulating, and retrieving the data from relational databases, For example, Oracle, MySQL, MongoDB, etc.

As the name, Structured Query Language suggests it works on structured data, Which means it works on tabular data which is related to each other.

Do You Know? SQL is developed by IBM researchers Raymond Boyce and Donald Chamberlin in the 1970s. SQL is completely based on a relational database.

As the name, Structured Query Language suggests it works on structured data, Which means it works on tabular data which is related to each other.

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SYNTAX:

Syntax of SQL uses the commands, functions, operators, and clauses according to the problem or the query.

There are a unique set of rules and regulations in SQL syntax, which is not case-sensitive. Its Syntax is defined and maintained by the ISO and ANSI standards.

Some impotent points about the syntax of SQL:

• You can write the keywords in SQL in both uppercase and lowercase, but writing the SQL keywords in uppercase improves the readability of the SQL query.

• SQL statements or syntax are dependent on text lines. We can place a single SQL statement on one or multiple text lines.

• You can perform most of the actions in a database with SQL statements.

• SQL syntax depends on relational algebra and tuple relational calculus.

example

SELECT COLUMN_NAME1, COLUMN_NAME2,....
FROM TABLE_NAME
WHERE < CONDITIONS AND OPERATORS ARE USED >;

OR

SELECT * FROM TABLE_NAME;

The above syntax is the basic syntax to retrieve the data from the table according to the condition or retrieve all the data from the table. you will understand the syntax and query better in the further blog post.

NOTE: SQL is used only for a relational database.

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SQL CAN DO THE FOLLOWING:

• Modifying database table and index structures.

• Adding, Updating, and Deleting rows of data.

• Retrieving subsets of information from within relational database management systems (RDBMS) -- this information can be used for transaction processing, analytics applications, and other applications that require communicating with a relational database.

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MAJOR FIELDS IN WHICH SQL IS USED:

SQL is widely used in the fields of Data Analytics and Data Science because of the fundamental use of the SQL by data professionals and SQL users to insert, update, modify, and delete the data in the relational database.

SQL allows the data professionals and users to retrieve and helps in creating a view, stored procedures, and functions in a relational database management system. It also helps to describe the structured data for the users.

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SQL COMMANDS:

SQL is basically designed to access, modify and extract the data from a relational database. According to the operations, the SQL commands are divided into the following:

• DDL ( Data Definition Language )

• DML ( Data Manipulation Language )

• DQL ( Data Query Language )

• DCL ( Data Control Language )

• TCL ( Transaction Control Language )

You will get to know all the SQL commands in the further blog posts.

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