Dapper is a lightweight, open-source Object-Relational Mapping (ORM) library for .NET, developed by Stack Exchange. It simplifies database interactions by allowing developers to execute SQL queries and map results directly to .NET objects with minimal boilerplate code.
### Key Features:
1. **Performance**: Dapper is designed for speed, often outperforming other ORM frameworks by executing raw SQL and minimizing overhead.
2. **Simplicity**: It provides a straightforward API that makes it easy to use, especially for developers familiar with SQL.
3. **Flexibility**: Dapper supports multiple database systems, including SQL Server, MySQL, PostgreSQL, and SQLite.
4. **Strongly Typed**: It maps query results to strongly typed objects, which enhances type safety in applications.
5. **Partial Mapping**: You can map only the properties you need, which can optimize performance and memory usage.
6. **Support for Advanced Queries**: Dapper can handle complex queries, including joins, and supports stored procedures.
### Use Cases:
- When high performance is essential and the overhead of a full ORM is not justified.
- In applications that require straightforward database interactions without extensive mapping configurations.
### Example:
Here's a simple example of using Dapper to query a database:
```csharp
using (var connection = new SqlConnection(connectionString))
{
connection.Open();
var result = connection.Query<User>("SELECT * FROM Users WHERE Age >
@Age", new { Age = 18 });
}
```
In this example, the `Query` method executes a SQL command and maps the results to a list of `User` objects.
### Conclusion:
Dapper is an excellent choice for developers looking for a lightweight and efficient way to interact with databases in .NET applications. Its balance of performance and simplicity makes it a popular choice in many projects.