Dapperer

Dapperer is an extension for Dapper. It uses attributes on a database POCO entity classes to facilitate the followings.

• A generic repository for basic CRUD operations on a relational database with no SQL query.
• Populating sub entities
• Page-able queries
• Cache-able query builder for the basic CURD operation queries.

Nuget

https://www.nuget.org/packages/Dapperer

To install Dapperer, run the following command in the Package Manager Console

PM> Install-Package Dapperer

Walk-through by example - Dapperer.TestApiApp

This is just a test application, ignore that the database entities are exposed to outside and error handling etc.

Database entities and Attributes

[Table("Contacts")]
public class Contact : IIdentifier<int>
{
    [Column("Id", IsPrimary = true, AutoIncrement = true)]
    public int Id { get; set; }

    [Column("Name")]
    public string Name { get; set; }

    public List<Address> Addresses { get; set; }

    public void SetIdentity(int identity)
    {
        Id = identity;
    }

    public int GetIdentity()
    {
        return Id;
    }
}

A database entity class must be extended from IIdentifier<TPrimaryKey>

• Table attribute is to specify table name
• Column attribute is to specify column name and more such as
  • IsPrimary - Primary key or not
  • AutoIncrement if not auto increment then the key must be set before add/update an entity

Repositories

public class ContactRepository : Repository<Contact, int>
{
    public ContactRepository(IQueryBuilder queryBuilder, IDbFactory dbFactory)
        : base(queryBuilder, dbFactory)
    {
    }

    public virtual void PopulateAddresses(Contact contact)
    {
        PopulateOneToMany<Address, int>(address => address.ContactId, c => c.Addresses, contact);
    }

    public virtual Contact GetContactByName(string name)
    {
        ITableInfoBase tableInfo = GetTableInfo();
        string sql = string.Format(@"SELECT * FROM {0} WHERE Name = @Name", tableInfo.TableName);

        using (IDbConnection connection = CreateConnection())
        {
            return connection.Query<Contact>(sql, new { Name = name }).SingleOrDefault();
        }
    }
}

Dapperer conversion for repository is one concrete repository per database entity. A concrete repository (ContactRepository in the above case) must be extended from the base Repository<TEntity, TPrimaryKey> which provides all the basic CRUD operations, page-able queries, etc. You can enjoy everything dapper provides in the extended repository class, GetContactByName is an example for writing your own custom queries.

Caching basic queries

In this current implementation of the Dapperer all the basic CRUD queries are cached in-memory. This need a single instance of a single Query builder for the lifetime of your applications. This can be wired using dependency injection. In the test application used in this Walk-through uses Autofac, and its binding as follow.

builder.RegisterType<SqlQueryBuilder>().As<IQueryBuilder>().SingleInstance();

Configurations

Dapperer need a concrete implementation of IDappererSettings, instead you could use DefaultDappererSettings. This currently require the following application settings.

<add key="Dapperer.ConnectionString" value="Server=localhost;Database=dapper_test;Trusted_Connection=True;" />

Databases

Dapperer can be extended for different databases other than SQL database you must create the following for any new databases

• QueryBuilder for the database which extends IQueryBuilder
• DbFactory for creating database connection which extends IDbFactory