specification-pattern

Implement the Specification pattern for .NET query criteria with Entity Framework Core.

Updated Jan 20, 2026

Search Tags:#specification #repository #query #c##entity framework #design-pattern

Ready to run

npx skills add https://github.com/AdrianAVA9/cero-base --skill specification-pattern-adrianava9

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: specification-pattern
Source: https://github.com/AdrianAVA9/cero-base/tree/main/.agents/skills/specification-pattern
Command: npx skills add https://github.com/AdrianAVA9/cero-base --skill specification-pattern-adrianava9

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) and assets (resource) components.

What problem does it solve?

This Skill addresses the challenge of writing maintainable and reusable query logic by encapsulating criteria into specification classes, reducing code duplication.

Core Features & Use Cases

Encapsulates query conditions: Define criteria once and reuse across different parts of the application.
Enables composition: Combine multiple specifications with logical operators like And/Or.
Supports includes, ordering, and pagination: Manage complex query behavior with minimal boilerplate.
Use Case: A developer wants to filter active users, include related data, sort by name, and paginate results seamlessly.

Quick Start

Use the specification pattern to create flexible queries by defining specifications and applying them with the evaluator.

Frequently Asked Questions about specification-pattern

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is the specification pattern in C# and when should I use it?▼

The specification pattern encapsulates query criteria into reusable, composable classes, reducing code duplication. You should use it when you need to define complex, testable query conditions for .NET applications that can be combined with logical operators and shared across your codebase.

How do I build composable queries with Entity Framework Core?▼

You build composable queries by defining separate specification classes for each criterion and combining them using And/Or logical operators. This approach lets you manage includes, ordering, and pagination with minimal boilerplate, streamlining complex data retrieval in Entity Framework Core.

Can I use the specification pattern to handle includes, sorting, and pagination together?▼

Yes, the specification pattern supports managing complex query behavior including related data includes, ordering, and pagination. By encapsulating these parameters within a specification class, you apply them seamlessly through an evaluator to retrieve exactly the data you need.

What is the best way to avoid duplicating query logic across different repositories?▼

The best way to avoid duplicated query logic is to encapsulate your filtering conditions into reusable specification classes. By defining criteria once, you can apply the same specification across different repositories, ensuring your data access layer remains maintainable.

Does this specification pattern implementation work without any external dependencies?▼

Yes, this implementation has no external dependencies. It is designed to integrate directly with Entity Framework Core, allowing you to implement reusable and testable query criteria using only your existing .NET application environment.

How do I test complex query criteria in a .NET application?▼

You test complex query criteria by encapsulating the conditions into specification classes. Because each specification is an isolated object, you can unit test the query logic independently of the database, ensuring your Entity Framework Core data retrieval behaves correctly.