Introduction to Structured Query Language (SQL)

Data Storage

• Data is stored as files on computers, just like images, documents, audio/videos, etc.
• School/hospital data is also stored in data files.
• Data can be translated into a form for efficient movement and processing, making it interchangeable.

Database

• A database is a collection of organized data that is structured and stored electronically on a computer system.
• Databases can store data in the form of tables, depending on the type of database.
• The primary goal of a database is to store a huge amount of data.
• Databases are used to store a large number of dynamic websites on the Internet today.
• Data can be accessed, managed, updated, regulated, and organized efficiently in a database.
• Most databases use Structured Query Language (SQL) for writing and retrieving data.

Relational Databases

• The most popular form of database today is the relational database.
• Examples of relational databases include Microsoft Access, MySQL, and Oracle.
• A relational database organizes data into one or more tables, with each table having a set of fields that define the nature of the data stored.

Benefits of DBMS

• Data Security: DBMS provides mechanisms for ensuring the security and integrity of the data stored in the database.
• Data Consistency: DBMS ensures that the data in the database is consistent by enforcing data validation rules, transaction management, and recovery mechanisms.
• Concurrent Access and Recovery: DBMS allows multiple users to access the database concurrently while ensuring that the data remains consistent and that data loss is minimized in case of system failures.
• Reduced Application Development Time: DBMS provides an interface for the application program to interact with the database, reducing the time and effort required to develop and maintain the application.
• Backup and Recovery: DBMS provides backup and recovery mechanisms to protect against data loss due to system failures or other disasters.
• Data Sharing: DBMS enables data sharing and integration across different applications and systems.
• Improved Performance: DBMS provides query optimization, indexing, and other mechanisms to improve the performance of database operations.

Applications of DBMS

• DBMS is extensively used in real-time systems due to its adaptability to various use cases.
• DBMS is used in banking, education, transport, tourism, human resource management, manufacturing, and e-commerce for storing data and analyzing insights.

RDBMS Advantages

• RDBMS allows the establishment of relationships between tables using keys (primary and foreign keys).
• RDBMS provides robust security features, including user authentication, access control, and encryption, to protect sensitive data from unauthorized access and ensure data privacy.
• RDBMS provides data independence by separating the physical data storage from the logical data representation.

SQL and its Importance

• SQL stands for Structured Query Language, which is a standard programming language used to manage relational databases and manipulate the data they contain.
• SQL is used to create and modify database schema, insert, update, and delete data in tables, and retrieve data from tables based on specific criteria.
• SQL is a declarative language, which means that you specify what you want to do with the data, rather than how to do it.

Introduction to SQL

• SQL serves as a cornerstone in understanding and manipulating data within databases.
• SQL involves learning data types, constraints, and the practical application of SQL statements through lab sessions.
• SQL syntax includes commands such as SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, and ALTER.

Data, Field, Record, and Database

• Data can be any information, thought, or media that is being transferred from one person to another.
• Data can be text, numbers, characters, bytes, images, etc.
• A record is one instance of a set of fields in a table, representing a single entry or instance.
• A field contains data about one aspect of the table subject, such as first name, last name, or email address.
• A database is a collection of organized data that is structured and stored electronically on a computer system.

Basic Concepts of DBMS and RDBMS

• DBMS is a software used for the storage, access, and manipulation of data.
• DBMS helps in securing data and getting useful insights from it.
• Key features of DBMS include data abstraction and independence, making it easier to manage data and making the system more flexible.

Explore the fundamentals of SQL, from data types and constraints to practical application of SQL statements. Learn how to define, retrieve, modify, and manage data using various SQL statements, including functions like Count, Sum, Min, Max, Avg, and Group By.