Lightmap is a simple, fast, database modeling API for .Net projects.

Note: this project is still under heavy development. NuGet packages haven't been shipped and breaking API changes should be expected.

Summary

• Define data model independently of data store.
• Use different databases across different environments with the same data model and code.
• Supported runtimes: .NET Core, Full .NET Framework and Mono.
• Supported Languages: C#, Visual Basic.
  • F# should work as well, but has not been tested.

Features

• Table constraints
  • Foreign Key
  • Unique
  • Not Null
• Migration support
  • Migrate a database forward
  • Migrate a database backward
  • Automatic migration discovery
  • Datamodel version tracking

Examples

Performing a migration

You can migrate your database to new datamodels by defining the new model in a class that implements the IMigration interface.

public class InitialDataModel : IMigration
{
public InitialDataModel(IDataModel currentModel) => this.DataModel = currentModel;
public IDataModel DataModel { get; }
public void Apply()
{
DataModel.AddTable("dbo", "User")
.AddColumn(typeof(int), "Id").GetOwner()
.AddColumn(typeof(string), "Name");
}
public void Revert()
{
// Code to revert:
}
}

Once you have one or more migrations defined, you can process them with the datastore of your choice, providing it has an implementation of IDatabaseManager and IDatabaseMigrator.

public class Program
{
public static void Main()
{
IDatabaseManager databaseManager = new SqliteDatabaseManager("MyDatabase", "DATA SOURCE=MyDatabase");
IDataModel dataModel = new DataModel();
IMigration initialMigration = new InitialDataModel(dataModel);
IDatabaseMigrator migrator = new SqliteMigrator(initialMigration);
// Apply migration to database.
migrator.Apply(databaseManager);
}
}

Untyped Data Modeling

You can model database tables with just strings and Types.

var dataModel = new DataModel();
dataModel.AddTable(schemaName: "dbo", tableName: "Foo")
.AddColumn(typeof(int), "Id")
IsPrimaryKey()
.AddColumn(typeof(string), "Name")
.AddColumn(typeof(DateTime), "CreatedOn")
.AddColumn(typeof(int), "LastState")
.IsNullable();

Strongly typed Modeling

Strongly typing your database tables provides a little more safety, ensuring that your constraints and references all are correctly spelled.

When a Type is provided as the table generic argument, all of the properties on the model are turned into columns. You may then alter individual properties as needed.

var dataModel = new DataModel();
dataModel.AddTable<AspNetRoles>("dbo")
.AlterColumn(model => model.Id)
.IsPrimaryKey()
.GetOwner()
.AlterColumn(model => model.Name)
.Unique()

Strongly typed with Anonymous objects

Lightmap allows you to create your tables with anonymous objects, so you can still have a strongly typed data model, without having to create a bunch of classes yourself.

var dataModel = new DataModel();
dataModel.AddTable("dbo", "Foo", () => new
{
Id = default(Guid),
Name = default(string),
CreatedOn = default(DateTime)
})
.AlterColumn(model => model.Id)
.IsPrimaryKey()
.AlterColumn(model => model.Name)
.Unique();