n2.core.entity 1.0.9

N2.Core.Entity

Classes

ChangeLog : IChangeLog

The class ChangeLog implements the interface IChangeLog and represents a change log entry. It is used to store information about changes made to an entity. The structure of the model can be used as a template for other record definitions. It features:

- `Id` : `int` : The unique identifier of the change log entry.
- `LogRecordId` : `Guid` : A unique identifier for external references.
- `ReferenceId` : `Guid` : The unique identifier of the entity that was changed.
- Other columns to store information about the change.
- A static BuildModel method to define the structure of the model.

Define the ChangeLog in the data context where you want to implement change tracking. If you define a datacontext usig the CoreDataContext class, the ChangeLog class is added by default.

public class MyDataContext(DbContextOptions options) : DbContext(options)
{
    public virtual DbSet<ChangeLog> ChangeLog { get; set; }

	 protected override void OnModelCreating([NotNull] ModelBuilder modelBuilder)
	 {
		 base.OnModelCreating(modelBuilder);

		 // Add the ChangeLog model(s) to the data context.
		 ChangeLogBuilder.BuildModel(modelBuilder);
	 }
}

ChangeLogBuilder

The ChangeLogBuilder class provides a static method to define the structure of the ChangeLog model. For a set of tables that have some common goal, a static builder class should be defined to set up the data context. The BuildModel method is used to define the structure of the model. Call this method from the OnModelCreating method of the data context.

DbBaseModel : IDbBaseModel

The DbBaseModel class implements the IDbBaseModel interface and represents a base model for all entity classes. It is used to store common properties that are shared by all entities. The structure of the DbBaseModel contains basic tracking information. A few things to note:

- `Id` : This is the primary key, and it is automatically assigned by the database. It is an integer
  as this is the type that is easily sorted and indexed.
- `PublicId` : This is a unique identifier that is used to identify the entity in a public context.
  This is useful when the entity is exposed to the public, as the internal identifier should not be.
- RowVersion : This is a timestamp that is used to track changes to the entity. It is used to prevent
  concurrent updates to the same entity. Using a timestamp is more efficient than using a date-timé
  values and is more reliable than using a version number.A bonus is that Entity Framework Core
  recognizes a timeatamp as a concurrency token.
- The BuildModel method is used to define the structure of the model. It should be called from
  the buildmodel method of any derived class.

EntityConnectionService : IEntityConnectionService

The EntityConnectionService class implements the IEntityConnectionService interface and is used to read connection string information from the configuration.