Query
In databases, a query is a request to retrieve, insert, update or delete data. Written in SQL (Structured Query Language), queries can be simple, like fetching all rows from a table, or complex, involving joins, conditions and aggregations. They are essential for interacting with and managing database information efficiently.
Top Query Articles
Constraints in SQL
what is Constraints ? how to add Constraints in SQL column? use case of Constraints in SQL?. In SQL, Constraints are rules applied to table column(s) or entire tables to enforce data integrity and reliability. Constraints are essential for defining how data should be stored and retrieved. Constraints help prevent invalid data entry and maintain the consistency and accuracy of the data.
How to Drop a Table in SQL
DROP TABLE command in SQL is part of the Data Definition Language (DDL) and is used to permanently delete a table from a database. This action is irreversible and deletes the table structure, its data and associated metadata, including indexes, constraints and permissions.
Temporary Table in SQL
Temporary Table in SQL. What is Temporary Table in SQL? How to create a temporary Table in SQL? As the name describes , a temporary table is a table created to store temporary data in the database. You can perform SQL operations similar to the permanent table, such as CREATE, UPDATE, DELETE, INSERT, JOIN and more. Temporary tables are automatically deleted when the current client session is terminated. If needed, you can also explicitly delete a temporary table within the session.
Cloning Table in SQL
Cloning a table in Database Management is a common requirement when you want to create an exact or partial copy of an existing table, including its structure, data or both as per your business requirement. This feature is particularly useful in scenarios like testing, backup or creating a template for similar data storage.This operation can save significant time and effort when replicating table structures, attributes and data.
How to Rename a Tables in SQL
Rename Table command in SQL | how to rename a table in a database | how to rename a table in SQL | rename tables in MYSQL, SQL Server and Oracle
How to Show Tables in SQL
SHOW Table command in SQL | how to show all tables in a database | list of all user define tables in SQL | show tables in MYSQL, SQL Server and Oracle | retrieve list of all database tables in relational database.
Foreign Key in SQL
SQL - Foreign Key - In SQL, a foreign key is a column (or a set of columns) in one table that uniquely identifies a row in another table. It establishes a relationship between the parent table (which contains the primary key) and the child table (which contains the foreign key).
Unique Key in SQL
Unique Key in SQL. Unique Key is a database constraint that ensures all the values in a column or a combination of columns are distinct. It prevents two records from having the same values in a unique Key column or set.
Primary Key in SQL
How to create Primary Key. Creating Primary Key syntax. A Primary Key is a database constraint that ensures uniqueness records in the table. Primary Key guarantees no two rows can have the same value in the primary key column(s). The Primary Key not only ensures uniqueness but also improves data access speed and is used to establish relationships between tables.
Database Backup in SQL
Databases are designed to store, manage and retrieve data efficiently. Data integrity (accuracy, consistency, and reliability) and security are crucial in databases. Database backup is one of the most important aspects of maintaining data. Database backup ensures that in case of system failures, hardware failures or accidental data loss. Your data is safe, recoverable and protected. In this article, we will explore the importance of database backups, the different types of backups with examples.
Popular Topics
GitGit Commitgit branchArchitecturegit pullLanguage-Conceptsgit commandsGitHubJavaHashMap
Git is an open-source distributed version control system.
Git Commit
git branch is a command used to manage branches
architecture
git pull is a command used to fetching changes form remote repo
This tag is used to understand a basic part of the language.
List of all git commands
GitHub is a web-based hosting service for software development projects that use Git for version control.
Java is a high-level object-oriented programming language. it's firstly released by Sun Microsystems in 1995. Use this tag when you're having queries using or understanding the language. This tag is also applicable to Java libraries and frameworks.
A HashMap is a data structure that stores key-value pairs using hashing for fast access, insertion and deletion. Keys are unique and each maps to exactly one value. It offers average O(1) time complexity for basic operations and is widely used for efficient lookups, caching and data mapping in applications.
Popular Articles
List Handling in Java vs C# vs C++ A Deep Comparison, This comparison provides a full view java , c# and c++ List like data structures
How to Approach HR Interview Questions , What to Keep in Mind While Answering HR Interview Questions, HR Interview Questions and Answers
Maximum Product Subarray, Find Maximum Product Subarray in an Array, Given an integer array arr, find a subarray that has the largest product,
Mastering the Singleton Design Pattern in C#, Singleton Design Pattern in Depth: Structure, Use Cases and Best Practices, in depth design pattern, LLD , low level design
How to create Primary Key. Creating Primary Key syntax. A Primary Key is a database constraint that ensures uniqueness records in the table. Primary Key guarantees no two rows can have the same value in the primary key column(s). The Primary Key not only ensures uniqueness but also improves data access speed and is used to establish relationships between tables.
namespace in c# | namspace concept in c# | c# namespace | c sharp namespace | what is namesapce and it's use cases | why should we use namespace
Static Class vs Singleton in C#: A Complete Deep Dive
Mastering the Template Design Pattern in C#, Template Design Pattern in Depth: Structure, Use Cases and Best Practices
Top 50 SQL Interview Questions and Answers (Beginner to Intermediate). Top SQL Interview Questions for fresher. Frequently asked SQL interview questions with answers
Rotate an array of n elements to the right by k steps | right rotate the elements of an array | array rotate | rotate array by k step
Most Popular Tools
Explore our top online tools including a blank page for notes, a QR code generator, word counter and collaborative editor. These free, easy-to-use utilities help you write, analyze, share and organize content faster. Perfect for developers, creators and students to streamline everyday digital tasks efficiently.
Blank Page
Create a blank canvas for your ideas, notes or sketches. Use this tool for rough work and jotting down your thoughts
QR Code Generator
A QR Code Generator is a tool that instantly converts text, URLs or other data into a scannable QR code. Users can create custom QR codes for websites, contact info or messages. It's commonly used for quick access, sharing and printing without needing a backend or complex setup.
Word Counter
Perform various string operations like counting characters, words or letters.
Collaborative Editor
Collab Editor is a powerful, free-to-use online platform that lets you collaborate in real-time. Whether you re working on documents, brainstorming idea, or discussing projects etc