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ARAshifur Rahamansqlinsights.hashnode.devNov 27, 2025 · 5 min read

SQL Server Data Integrity & Constraints

Data Integrity ensures that the data in your database is accurate, consistent, and adheres to business rules. Constraints are the database objects that enforce these rules at the lowest level, preventing invalid data entry regardless of the applicati...

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GRGanesh Rama Hegdeandroidavatar.hashnode.devOct 28, 2025 · 6 min read

Chapter 6 - Coding the first Use case (Data layer)

We coded the domain layer classes in the earlier chapter. Now we need to write the classes of data layer so that the use case becomes more meaningful in nature. The GetArtUseCase will fetch the list of Art objects from the local Room database. This i...

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KKKrishal Karnacompletesql.hashnode.devAug 14, 2025 · 8 min read

Introduction to Databases and MySQL

Imagine you’re sitting in an interview. The interviewer looks at you and asks,"What is data?" You might be tempted to say something like, “Data is anything that exists on Earth… numbers, letters, symbols, all of that right?” Then they hit you with th...

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YSYash Sakhareliyalearn-pgsql.hashnode.devJul 15, 2025 · 3 min read

Understanding SQL Table Relationships And Keys

In relational database design, understanding how tables relate to each other is critical. Whether you're building a social media platform, e-commerce system, or blog site, you’ll encounter different types of relationships. In this article, I’ll walk ...

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JNJayRam Naijramnai.hashnode.devMay 11, 2025 · 1 min read

Fixing Non-Incrementing Primary Key in PostgreSQL

Problem While inserting data into a PostgreSQL table, I got this error: ERROR: Key (“userId“)=(1234) already exists.duplicate key value violates unique constraint “User_pkey“ SQL state: 23505 Details: Key (“userId“)=(1234) already exists. The userId...

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GRGanesh Rama Hegdevedicschema.hashnode.devApr 5, 2025 · 4 min read

2. Tables, Entities, and RDBMS

In a database design design we are discuss these three important topics - Tables, Entities and RDBMS. You may ask why ? Aren’t you digressing from the topic ? I would like to say that we would be using these concepts as the building blocks of our des...

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GRGanesh Rama Hegdevedicschema.hashnode.devApr 5, 2025 · 3 min read

1. Databases, Database Design and SQL

In today’s modern digital world dominated by Artificial Intelligence and Machine Learning, data is the new fuel. Data is at the core of every application - from fitness apps, healthcare and e-commerce to banking and social media. We use databases to ...

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GRGanesh Rama Hegdevedicschema.hashnode.devApr 5, 2025 · 4 min read

3. SQL (Structured Query Language) - Part 1

What is SQL ? SQL (Structured Query Language) is the standard language used to create, read, update, and delete data in a relational database. Why is SQL important ? It allows us to communicate with the database and manage data effectively. Types of ...

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UUtkarshblogs.utkarshrajput.comSep 23, 2024 · 7 min read

UUID or Auto Increment Integer: Best Primary Key for your DB

Introduction If you've found yourself asking the same age-old question: “Should I use UUIDs or auto-incrementing integers for my primary keys?”—congratulations! You're officially one of us, a developer with existential dilemmas. It’s like choosing be...

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RRRicardo Ribeirokaitozr.hashnode.devJun 5, 2024 · 2 min read

Coletando ids do banco de dados (.NET x SQL SERVER)

Trabalhando com edição de dados no banco utilizando o .NET, encontrei a dificuldade de puxar as keys do banco de dados para o código no Visual Studio. A primeira solução que pensei para isso foi criar uma textBox que serviria como um placeholder que ...

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#primary-key

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Trending tags this week

SQL Server Data Integrity & Constraints

Chapter 6 - Coding the first Use case (Data layer)

Introduction to Databases and MySQL

Understanding SQL Table Relationships And Keys

Fixing Non-Incrementing Primary Key in PostgreSQL

2. Tables, Entities, and RDBMS

1. Databases, Database Design and SQL

3. SQL (Structured Query Language) - Part 1

UUID or Auto Increment Integer: Best Primary Key for your DB

Coletando ids do banco de dados (.NET x SQL SERVER)