ASP.NET Core Complete Tutorial (ShopNest)
Lesson 56 of 75 75% of course

Testing EF Core — In-Memory vs SQLite

1 · 5 min · 5/24/2026

Learn Testing EF Core — In-Memory vs SQLite in our free ASP.NET Core Complete Tutorial (ShopNest) series. Step-by-step explanations, examples, and interview tips on Toolliyo Academy.

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Testing EF Core — In-Memory vs SQLite — ShopNest
Article 56 of 75 · Module 7: Testing · ShopNest Repository Layer Testing
Target keyword: testing ef core · Read time: ~30 min · .NET: 8 / 9 · Project: ShopNest Repository Layer Testing

Introduction

ShopNest repository tests need a database — EF InMemory is fast but lies about SQL behavior; SQLite in-memory runs real SQL and catches more bugs.

After this article you will

  • Compare EF InMemory vs SQLite test providers
  • Seed test data and test complex LINQ queries
  • Choose fresh DbContext per test vs shared
  • Test repository and specification implementations
  • Reset databases with Respawn

Prerequisites

Concept deep-dive

ProviderProsCons
EF InMemoryFastest, no SQLNo FK constraints, different semantics
SQLite memoryReal SQL, relationalNot 100% SQL Server identical
SQL Server LocalDBClosest to prodSlower, CI setup harder
private ShopNestDbContext CreateContext()
{
    var options = new DbContextOptionsBuilder<ShopNestDbContext>()
        .UseSqlite("DataSource=:memory:")
        .Options;
    var ctx = new ShopNestDbContext(options);
    ctx.Database.OpenConnection();
    ctx.Database.EnsureCreated();
    SeedTestProducts(ctx);
    return ctx;
}

[Fact]
public async Task GetByRegion_ReturnsFilteredCustomers()
{
    using var ctx = CreateContext();
    var repo = new CustomerRepository(ctx);
    var spec = new CustomersByRegionSpec("South");
    var result = await repo.ListAsync(spec);
    Assert.All(result, c => Assert.Equal("South", c.Region));
}

Hands-on — ShopNest Repository Layer Testing

  1. Repository tests with SQLite :memory: per test.
  2. Test Include/specification SQL-heavy queries.
  3. Document InMemory failures (Ignore FK) you hit once.
  4. Respawn reset for integration test SQL Server.

Common errors & best practices

  • InMemory for testing transactions — not supported reliably.
  • Shared context mutated across parallel tests — disable parallel or isolate.
  • Assuming SQLite = SQL Server — test critical queries on real SQL in CI.

Interview questions

Q: Why not InMemory?
A: Ignores constraints and provider-specific SQL — SQLite closer to real.

Q: EnsureCreated vs Migrate?
A: EnsureCreated for tests; Migrate if testing migration scripts.

Summary

  • Prefer SQLite in-memory over EF InMemory for repos
  • Seed minimal data per test for clarity
  • Test specifications against real LINQ-to-SQL
  • Respawn cleans SQL Server between integration tests

Previous: Integration Testing
Next: Performance and Load Testing

FAQ

Test migrations?

Use Migrate() against LocalDB or Testcontainers SQL.

Parallel repo tests?

Unique database name per test collection.

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ASP.NET Core Complete Tutorial (ShopNest)

On this page

Introduction After this article you will Prerequisites Concept deep-dive Hands-on — ShopNest Repository Layer Testing Common errors &amp; best practices Interview questions Summary FAQ Test migrations? Parallel repo tests?
Module 1: Foundations
What is ASP.NET Core? Complete Guide Setting Up ASP.NET Core Development Environment ASP.NET Core Project Structure Explained MVC Architecture in ASP.NET Core — Complete Guide Controllers and Actions in ASP.NET Core Routing in ASP.NET Core — Conventional and Attribute Routing Views and Razor Syntax in ASP.NET Core Layouts, Partial Views and View Components Models and ViewModels in ASP.NET Core Forms, Model Binding and Validation in ASP.NET Core Tag Helpers in ASP.NET Core — Complete Guide Static Files, Bundling and Minification in ASP.NET Core
Module 2: Entity Framework Core
Entity Framework Core — Introduction and Setup EF Core Code First — Models, Migrations, Database EF Core CRUD Operations — Create, Read, Update, Delete EF Core LINQ Queries — Beginner to Advanced EF Core Relationships — One-to-One, One-to-Many, Many-to-Many EF Core Fluent API — Advanced Configuration EF Core Repository Pattern and Unit of Work EF Core Performance Optimization Database First Approach with EF Core (Scaffold) EF Core with SQL Server — Advanced Features
Module 3: Dependency Injection & Middleware
Dependency Injection in ASP.NET Core — Complete Guide Middleware in ASP.NET Core — Complete Guide Configuration in ASP.NET Core — appsettings, Environment Variables, Secrets Filters in ASP.NET Core — Action, Authorization, Exception, Resource, Result Logging in ASP.NET Core — ILogger, Serilog, NLog Error Handling and Exception Management in ASP.NET Core
Module 4: Authentication & Security
ASP.NET Core Identity — Complete Setup Guide Authentication in ASP.NET Core — Cookie and JWT Authorization in ASP.NET Core — Roles, Policies, Claims JWT Authentication with Refresh Tokens — Complete Implementation OAuth2 and External Login (Google, Facebook, Microsoft) Data Protection and Encryption in ASP.NET Core HTTPS, SSL Certificates and Security Best Practices
Module 5: Web API
Building REST APIs with ASP.NET Core — Complete Guide API Versioning in ASP.NET Core Swagger / OpenAPI Documentation in ASP.NET Core Input Validation in Web APIs — FluentValidation and Data Annotations Pagination, Filtering and Sorting in ASP.NET Core APIs HTTP Client and Consuming External APIs in ASP.NET Core Minimal APIs in ASP.NET Core .NET 8 SignalR — Real-Time Web Applications
Module 6: Advanced Architecture
Clean Architecture in ASP.NET Core CQRS Pattern with MediatR in ASP.NET Core Repository Pattern — Deep Dive with Generic Repository Background Services and Hosted Services in ASP.NET Core Caching in ASP.NET Core — In-Memory, Distributed, Redis Health Checks in ASP.NET Core AutoMapper in ASP.NET Core Microservices with ASP.NET Core — Introduction Message Queues with RabbitMQ / Azure Service Bus in ASP.NET Core gRPC with ASP.NET Core
Module 7: Testing
Unit Testing ASP.NET Core with xUnit and Moq Integration Testing in ASP.NET Core Testing EF Core — In-Memory vs SQLite Performance Testing and Load Testing ASP.NET Core APIs Test-Driven Development (TDD) in ASP.NET Core
Module 8: Deployment & DevOps
Deploying ASP.NET Core to IIS on Windows Server Docker and Containerization for ASP.NET Core Deploying ASP.NET Core to Azure App Service CI/CD with GitHub Actions for ASP.NET Core Azure SQL Database with ASP.NET Core Environment Configuration and Secrets Management
Module 9: Real-World Projects
Build a Complete Blog Website with ASP.NET Core MVC Build an E-Commerce Product Catalog API (ASP.NET Core Web API) Build a Student Management System (Complete CRUD App) Build a Job Portal (Full Stack ASP.NET Core) Build a REST API with Clean Architecture — Complete Guide Build a Real-Time Chat App with SignalR and ASP.NET Core
Module 10: Advanced Topics
Blazor WebAssembly and Blazor Server — Complete Guide gRPC, GraphQL and Alternative API Styles in ASP.NET Core Rate Limiting and API Throttling in ASP.NET Core .NET 8 Output Caching in ASP.NET Core .NET 8 ASP.NET Core .NET 9 New Features — Complete Guide