🚀 How to Build Dynamic LINQ Queries Easily with WhereDynamic in .NET8+

Source: Dev.to

Introducing WhereDynamic

We’ve all been there: writing endless if statements to build conditional queries, or duplicating logic across multiple endpoints just to handle different filter combinations. It’s messy, error‑prone, and hard to maintain.

The Problem

When building APIs or data‑driven applications with .NET and Entity Framework, we often need to apply filters based on user input. Traditional approaches lead to bloated code.

The Solution

WhereDynamic provides a concise, type‑safe way to compose LINQ Where clauses at runtime, eliminating repetitive conditional logic while preserving full EF Core translation to SQL.

Practical Use Cases

1. Advanced Search Filters

Build complex search pages where users can combine arbitrary criteria (e.g., date ranges, text matches, numeric ranges) without writing a separate query for each combination.

2. Multi‑Tenant Data Filtering

Apply tenant‑specific filters automatically, ensuring each request only accesses data belonging to the current tenant.

3. API Query Parameters

Map query‑string parameters directly to LINQ predicates, enabling flexible, client‑driven filtering for REST or GraphQL endpoints.

4. Complex Nested Conditions

Compose nested AND/OR groups dynamically, supporting scenarios such as “(A AND B) OR (C AND (D OR E))” without hard‑coding the logic.

Key Benefits

• Cleaner Code – Eliminate repetitive conditional logic.
• Type Safety – Compile‑time checks with IntelliSense support.
• Performance – Translates directly to optimized SQL queries.
• Maintainability – Centralized filter logic, easier to test and extend.
• Flexibility – Works seamlessly with existing Entity Framework code.

Built For Modern .NET

WhereDynamic is built on .NET 8+, fully compatible with Entity Framework Core, and designed with performance and developer experience in mind. Whether you’re building REST APIs, GraphQL endpoints, or complex reporting systems, it adapts to your needs.