Dapper is a .NET Micro ORM, widely known as the “King of Micro ORMs”, delivering performance close to raw ADO.NET.

ORM: Object‑Relational Mapper, handles automatic mapping between database tables and C# entity objects.

Core features:

1. Does not wrap SQL; developers write SQL statements manually;
2. Extends IDbConnection via extension methods (usable with any database connection object);
3. Lightweight footprint with excellent performance.

Note: Technically it is a Micro ORM, different from full‑featured ORM frameworks such as EF Core. There is ongoing community debate over whether it qualifies as a pure ORM.

Preventing SQL Injection: Use parameterized queries to avoid injection risks; concatenating raw SQL remains unsafe.

Three‑Step Workflow: Create database connection → Write SQL statement → Call Dapper extension method to execute SQL with parameters.

Features

• High performance and fast query execution
• Supports mapping to static entities and dynamic objects
• Full control over SQL statements
• Multi‑result‑set query support
• Native stored‑procedure support
• Built on the IDbConnection interface, compatible with most database drivers
• Bulk insert support (extended capability; basic native bulk operations. For large‑scale bulk operations, use Dapper.Plus)

Installation

Option 1: NuGet Package Manager Console (PMC)

Install-Package Dapper

Option 2: .NET CLI (Recommended for .NET Core/.NET5+)

dotnet add package Dapper

Option 3: Visual Studio GUI

Solution Explorer → Right‑click your project → Manage NuGet Packages, search for Dapper and install it.

Important note: Dapper does not ship with database drivers!
For SQL Server install Microsoft.Data.SqlClient separately; for MySQL install MySqlConnector.

Example

using Dapper;
using Microsoft.Data.SqlClient;

// 1. Initialize IDbConnection
string connStr = "Your database connection string";
using var conn = new SqlConnection(connStr);

// 2. Define SQL
string sql = "SELECT * FROM Article WHERE Id = @Id";

// 3. Execute query and auto‑map to entity
var article = conn.QueryFirstOrDefault<Article>(sql, new { Id = 1 });

public class Article
{
    public int Id { get; set; }
    public string Title { get; set; }
}

Comparison

Introduction & Installation