StringToNullableGuidPropertyHandler

A property handler that maps a text-based UUID column, such as the MariaDB UUID type, into a nullable Guid property.

A property handler that maps a text-based UUID column (for example, the MariaDB UUID type) into a Nullable<Guid> property.

Overview

Conversions

Exceptions

Usability

Bind the handler to the property that maps to a nullable UUID column.

Attribute

public class Session
{
    public int Id { get; set; }

    [Map("token"), PropertyHandler(typeof(StringToNullableGuidPropertyHandler))]
    public Guid? Token { get; set; }
}

Once bound, the library invokes the handler automatically when the property is read or written.

using (var connection = new MariaDbConnection(connectionString))
{
    connection.Insert(new Session { Id = 1, Token = null });
    var session = connection.Query<Session>(e => e.Id == 1).First();
    // session.Token is null
}

Fluent Mapping

To configure via FluentMapper:

FluentMapper
    .Entity<Session>()
    .PropertyHandler<StringToNullableGuidPropertyHandler>(e => e.Token);

Property Level Mapping

To configure via PropertyHandlerMapper:

PropertyHandlerMapper.Add<Session, StringToNullableGuidPropertyHandler>(e => e.Token, new StringToNullableGuidPropertyHandler(), true);

Type Level Mapping

To apply the handler to every property of the type Guid?:

PropertyHandlerMapper.Add<Guid?, StringToNullableGuidPropertyHandler>(new StringToNullableGuidPropertyHandler(), true);

A type level mapping is process-wide: it is applied to every Guid? property of every entity and connection, not only to the intended column. Prefer the attribute, fluent or property level mapping unless every Guid? property maps to a text-based UUID column.

See Also

• StringToGuidPropertyHandler