Dapper is a lightweight object mapper for .NET that maps the results of SQL queries directly onto plain objects with minimal overhead.
The tool solves the problem of bridging the gap between raw ADO.NET query results and strongly-typed objects without the complexity of a full ORM. It works by extending IDbConnection with methods that execute SQL commands and automatically map the returned data rows to object properties, allowing developers to write direct SQL while still gaining type safety and reduced boilerplate compared to manual result processing.
Dapper suits projects where developers prefer control over their SQL queries and want to avoid the performance penalties and learning curve of heavyweight ORMs. It works well in scenarios ranging from simple CRUD operations to complex queries where SQL optimization matters. The tool is particularly valuable in performance-sensitive applications and microservices where a minimal dependency footprint is important. Teams should choose Dapper if they are comfortable writing SQL directly and want an efficient bridge to objects rather than an abstraction layer that generates queries.
The project maintains a substantial base of real-world adopters, as evidenced by the fact that almost all open issues are raised by outside users rather than the core team. Maintainers typically respond to new issues and pull requests within a day.