Introduction

Dapper Extensions is a small library that complements Dapper by adding basic CRUD operations (Get, Insert, Update, Delete) for your POCOs. For more advanced querying scenarios, Dapper Extensions provides a predicate system. The goal of this library is to keep your POCOs pure by not requiring any attributes or base class inheritance.

Customized mappings are achieved through ClassMapper.

Important: This library is a separate effort from Dapper.Contrib (a sub-system of the Dapper project). Important: Check our projects list to see the plans for the next releases.

Features

Zero configuration out of the box.
Automatic mapping of POCOs for Get, Insert, Update, and Delete operations.
GetList, Count methods for more advanced scenarios.
GetPage for returning paged result sets.
Automatic support for Guid and Integer primary keys (Includes manual support for other key types).
Pure POCOs through use of ClassMapper (Attribute Free!).
Customized entity-table mapping through the use of ClassMapper.
Composite Primary Key support.
Singular and Pluralized table name support (Singular by default).
Easy-to-use Predicate System for more advanced scenarios.
Properly escapes table/column names in generated SQL (Ex: SELECT [FirstName] FROM [Users] WHERE [Users].[UserId] = @UserId_0)
Unit test coverage (150+ Unit Tests)

Naming Conventions

POCO names should match the table name in the database. Pluralized table names are supported through the PlurizedAutoClassMapper.
POCO property names should match each column name in the table.
By convention, the primary key should be named Id. Using another name is supported through custom mappings.

Installation

For more information, please view our Getting Started guide.

http://nuget.org/List/Packages/DapperExtensions

PM> Install-Package DapperExtensions

Examples

The following examples will use a Person POCO defined as:

public class Person
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public bool Active { get; set; }
    public DateTime DateCreated { get; set; }
}

Get Operation

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    int personId = 1;
    Person person = cn.Get<Person>(personId);   
    cn.Close();
}

Simple Insert Operation

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    Person person = new Person { FirstName = "Foo", LastName = "Bar" };
    int id = cn.Insert(person);
    cn.Close();
}

Advanced Insert Operation (Composite Key)

public class Car
{
    public int ModelId { get; set; }
    public int Year { get; set; }
    public string Color { get; set; }
}

...

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    Car car = new Car { Color = "Red" };
    var multiKey = cn.Insert(car);
    cn.Close();

    int modelId = multiKey.ModelId;
    int year = multiKey.Year;
}

Simple Update Operation

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    int personId = 1;
    Person person = cn.Get<Person>(personId);
    person.LastName = "Baz";
    cn.Update(person);
    cn.Close();
}

Simple Delete Operation

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    Person person = cn.Get<Person>(1);
    cn.Delete(person);
    cn.Close();
}

GetList Operation (with Predicates)

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    var predicate = Predicates.Field<Person>(f => f.Active, Operator.Eq, true);
    IEnumerable<Person> list = cn.GetList<Person>(predicate);
    cn.Close();
}

Generated SQL

SELECT 
   [Person].[Id]
 , [Person].[FirstName]
 , [Person].[LastName]
 , [Person].[Active]
 , [Person].[DateCreated] 
FROM [Person] 
WHERE ([Person].[Active] = @Active_0)

More information on predicates can be found in our wiki.

Count Operation (with Predicates)

using (SqlConnection cn = new SqlConnection(_connectionString))
{
    cn.Open();
    var predicate = Predicates.Field<Person>(f => f.DateCreated, Operator.Lt, DateTime.UtcNow.AddDays(-5));
    int count = cn.Count<Person>(predicate);
    cn.Close();
}