DatabaseMapper

DatabaseMapper is a lightweight .NET library that maps the results of SQL Server stored procedures to objects. No external mapping framework is involved: every returned column is assigned to the class property with the identical name.

How It Works

1. Create a DatabaseMapper instance with a SQL Server connection string.
2. Call one of the Execute* methods with the stored procedure name and an optional list of parameters.
3. The stored procedure is executed through System.Data.SqlClient, and each returned column is copied to the matching property of the target class.
4. After the call, stored procedure output parameters are available in the Parameters collection.

Features

• Maps the first result row to a single object (ExecuteSingle<T>).
• Maps all result rows to a List<T> (ExecuteList<T>).
• Executes non-query procedures and returns the number of affected rows (ExecuteNonQuery).
• Supports input and output parameters.
• NULL column values are skipped and leave the property at its default value.
• Single source file, only System.Data.SqlClient as the dependency.

Requirements

• .NET Framework 4.x
• SQL Server database reachable through System.Data.SqlClient

Usage

var mapper = new DatabaseMapper(connectionString);

// get a list of objects
var categories = mapper.ExecuteList<Category>("GetCategories");

// pass parameters
var parameters = new List<DatabaseMapper.DbParameter>();
parameters.Add(new DatabaseMapper.DbParameter("postID", System.Data.ParameterDirection.Input, postID));
var posts = mapper.ExecuteList<Post>("GetPosts", parameters);

// get a single object
var post = mapper.ExecuteSingle<Post>("GetPost", parameters);

// execute an insert/update/delete procedure
var affected = mapper.ExecuteNonQuery("DeletePost", parameters);

// read output parameters after the call
var outputValue = mapper.Parameters.Single(p => p.Name == "@result").Value;

Each mapped class needs a parameterless constructor, and the field names of the returned columns have to be identical to the property names of the class:

public class Category
{
    public int CategoryId { get; set; }
    public string Name { get; set; }
}

License

This project is licensed under the GNU General Public License v2.0 - see the LICENSE file for details.