PostgreSQL Commands and Data Types – A Complete Overview Introduction PostgreSQL is a powerful, open-source relational database management system widely used in modern applications. It is known for its reliability, performance, and rich support for advanced data types. Understanding SQL commands and PostgreSQL data types… Read More
Introduction to SQL Commands (DDL, DML,DQL, DCL, TCL) Beginner-Friendly Professional Documentation 1. SQL Basics & Command Categories What is SQL? SQL (Structured Query Language) is a standard language used to manage and interact with databases. Databases store data in the form of tables (rows and… Read More
Data Retrieval language(DRL) Data Retrieval Language (DRL) is a part of SQL used to retrieve (fetch) data from a database without modifying it. Main Command: SELECT – used to get data from one or more tables. Examples:
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SELECT * FROM students; → Retrieves all records from the students table. SELECT name, marks FROM students WHERE marks > 60; → Retrieves names and marks of students who scored more than 60. |
Purpose: ● To view data ● To… Read More
Data Definition Language (DDL) Introduction Structured Query Language (SQL) is the standard language used for interacting with relational databases. SQL is divided into different categories based on the type of operations performed on the database. Among these categories, Data Definition Language (DDL) plays a foundational… Read More
PostgreSQL: An In-Depth Overview of a Powerful Open-Source Database In today’s data-driven world, databases play a crucial role in storing, managing, and processing information efficiently. Almost every modern application—whether a web application, mobile app, enterprise system, or research platform—relies on a database at its core.… Read More
PostgreSQL Installation & Setup on macOS Introduction to PostgreSQL What is PostgreSQL? PostgreSQL is a powerful, open-source relational database management system (RDBMS). It is widely used by startups, enterprises, and developers because it is reliable, scalable, and similarly follows SQL standards. PostgreSQL supports: ● Structured… Read More
Introduction to SQL What is SQL? SQL (Structured Query Language) is a database computer language used to communicate with and retrieve data from relational databases. It allows users to store, manipulate, update, and retrieve data efficiently. SQL is widely used with popular database systems such… Read More
Linux / UNIX PATH, ls Command and File Access Permissions (Security) Introduction Linux and UNIX are powerful open-source operating systems widely used in servers, cloud platforms, development environments, and academic institutions. To work efficiently in Linux/UNIX, it is very important to understand PATH concepts, the… Read More
Linux / UNIX File and Directory Management Commands Introduction Linux and UNIX are powerful, open-source operating systems widely used in servers, cloud platforms, development environments, and academic institutions. File and directory management is a fundamental skill for working efficiently in UNIX/Linux systems. These operating systems… Read More
SQL SERVER INSTALLATION INTERNALS Installing Microsoft SQL Server is often treated as a routine DBA task : launch the installer, click Next a few times and wait for the green checkmark. But under the hood, SQL Server setup performs a carefully controlled sequence of validations,… Read More
