Introduction to Dapper in .NET Core

Introduction to Dapper in .NET Core

What is Dapper?

Dapper is a lightweight, high-performance micro Object-Relational Mapper (ORM) for .NET applications. Created by the team behind Stack Overflow, Dapper is widely used for interacting with relational databases. Unlike full-fledged ORMs like Entity Framework Core (EF Core), Dapper focuses on simplicity and speed while allowing developers to execute raw SQL queries and map the results to C# objects.

Purpose of Dapper

The main purpose of Dapper is to provide a minimalistic ORM solution that gives developers full control over their SQL queries while also mapping query results to C# objects with minimal overhead. This allows developers to work directly with SQL and still benefit from object-relational mapping without the complexity and performance overhead often associated with heavier ORMs like EF Core.

Why Use Dapper?

1. Performance Benefits
   One of the primary reasons to choose Dapper is performance. Dapper is extremely lightweight and operates with minimal overhead. While EF Core is feature-rich, it can come with added complexity that can slow down performance, especially when dealing with large datasets or complex queries.

• Dapper executes queries directly and does not track changes like EF Core. This results in lower memory consumption and faster execution speeds for simple CRUD (Create, Read, Update, Delete) operations.
• Dapper is particularly effective when your application requires high-performance data access with minimal abstraction over raw SQL queries.

2. Simplicity
   Dapper is easy to learn and use. It has a small API surface and doesn’t require you to learn complex configurations or conventions. Unlike EF Core, which uses LINQ (Language Integrated Query) and can abstract a lot of SQL work, Dapper allows you to write raw SQL queries.

• This simplicity makes Dapper a great choice for developers who are comfortable with SQL and prefer to work directly with it rather than dealing with an abstraction layer like EF Core.

3. Direct SQL Access
   With Dapper, you get the flexibility to write direct SQL queries, allowing you to leverage advanced SQL features (e.g., stored procedures, common table expressions) that might not be as straightforward to implement with EF Core.

• Dapper allows you to map query results to any class or structure, offering full control over the data representation in C#.
• If your database already contains stored procedures, Dapper makes it easy to execute them and map the results to C# objects without additional complexity.

How Does Dapper Differ from Entity Framework Core?

While both Dapper and EF Core are ORMs, they take different approaches to interacting with the database:

• Type of ORM

·       Dapper is a micro ORM, designed to be lightweight and efficient. It focuses on offering basic ORM functionality without the additional overhead found in larger frameworks.

·       Entity Framework Core (EF Core), on the other hand, is a full-fledged ORM that provides a wide array of features, including migrations, change tracking, and LINQ queries.

• Performance

• Dapper is known for its high performance and minimal overhead. Since it executes raw SQL queries directly, it runs much faster than EF Core, especially for simple CRUD operations.
• Entity Framework Core can be slower due to additional features like change tracking, which keeps track of entities that are added, modified, or deleted. This additional functionality adds overhead, affecting performance in certain scenarios.

• SQL Querying

• Dapper allows you to work with raw SQL queries. This provides full control over the SQL being executed and is particularly useful for complex queries, especially those relying on specific SQL features (like stored procedures or joins).
• Entity Framework Core abstracts SQL queries through LINQ, which provides a more structured, object-oriented way to interact with the database. However, this can limit flexibility when writing complex or optimized queries.

• Change Tracking

• Dapper does not include built-in change tracking. This means developers must manually handle the logic for updates, which can result in faster performance but requires more attention to detail.
• Entity Framework Core has built-in change tracking, automatically tracking modifications to entities and updating the database accordingly. This is convenient for developers but adds extra processing and memory usage.

• Ease of Use

• Dapper is simpler to use and is ideal for developers who are already comfortable with SQL. It requires less abstraction, meaning you need to explicitly write your SQL queries.
• Entity Framework Core is more complex but provides automatic mappings between C# objects and database tables, reducing the need for writing raw SQL. This makes it more beginner-friendly for developers who prefer not to interact directly with SQL.

• Learning Curve

·       Dapper has a low learning curve, making it quick for developers familiar with SQL to pick up.

·       Entity Framework Core has a steeper learning curve due to its feature-rich environment, which includes migrations, LINQ, and automatic model generation.

• Migration Support

• Dapper does not offer migration support. You need to handle database schema changes manually, which can be fine for simple applications or when using a database with an already established schema.
• Entity Framework Core offers full migration support, allowing you to define your schema using code (code-first) or generate models from an existing database (database-first). This makes it easier to manage schema changes.

• Flexibility

• Dapper offers maximum flexibility when it comes to SQL queries. Since it allows raw SQL execution, you can write any query you need, regardless of complexity.
• Entity Framework Core is less flexible because it abstracts database interactions. While EF Core is great for most scenarios, it can be restrictive when complex queries or specific SQL features are needed.

Conclusion on Dapper vs EF Core:
While EF Core provides more features, such as automatic migrations, change tracking, and LINQ queries, Dapper excels when you need speed, control, and simplicity for read-heavy applications or highly optimized SQL queries.

 

Installation and Setup

To get started with Dapper in a .NET Core application, follow these simple steps:

 

Step 1: Create a .NET Core Project

If you don’t already have a .NET Core project, create one by opening your terminal or command prompt and running:

dotnet new console -n DapperExample

cd DapperExample

 

Step 2: Install the Dapper Package

To use Dapper in your project, add the Dapper NuGet package by running:

dotnet add package Dapper

Alternatively, you can install it via NuGet Package Manager in Visual Studio.

 

Step 3: Install the Database Provider

For this example, we'll use SQL Server. Install the SQL Server provider by running:

dotnet add package System.Data.SqlClient

This allows your project to interact with SQL Server.

 

Step 4: Set Up the Database Connection

In Program.cs, import the necessary namespaces:

using System;

using System.Data.SqlClient;

using Dapper;

using System.Collections.Generic;

using System.Linq;

Step 5: Create a Connection

Now, set up a connection to your database. Replace your_connection_string with your actual connection string.

string connectionString = "your_connection_string";

using (var connection = new SqlConnection(connectionString))

{

    connection.Open();

    Console.WriteLine("Connection established.");

}

 

Step 6: Query Data with Dapper

Perform a simple query to fetch data. Assuming you have a Users table with columns Id, Name, and Email:

var users = connection.Query<User>("SELECT * FROM Users").ToList();

foreach (var user in users)

{

    Console.WriteLine($"{user.Id}: {user.Name} - {user.Email}");

}

 

Step 7: Define the Data Model

In the same file, define a User class to represent the queried data.

public class User

{

    public int Id { get; set; }

    public string Name { get; set; }

    public string Email { get; set; }

}

 

Conclusion

Dapper is a powerful yet lightweight ORM that offers performance and simplicity for .NET developers. It allows you to write raw SQL queries, giving you complete control over the SQL execution and lower memory usage. Dapper is an excellent choice when you want to balance simplicity and performance, especially in read-heavy applications or when dealing with complex queries that are difficult to handle with full-fledged ORMs like EF Core. By following these setup instructions, you can easily integrate Dapper into your .NET Core application and start benefiting from its speed and flexibility.