private AggregateRootSnapshot MakeSnapshot(SqlDataReader r, SnapshotOrdinal ordinal)
{
var type = Type.GetType(r.Field <string>(ordinal.Type));
var blob = r.Field <string>(ordinal.Blob);
return(type != null ? _serializer.ReadObject <AggregateRootSnapshot>(type, blob) : null);
}
/// <summary>
/// Gets the latest snapshot.
/// </summary>
/// <typeparam name="TAggregateRoot">The type of the aggregate root.</typeparam>
/// <param name="aggregateID">The aggregate ID.</param>
/// <returns></returns>
public AggregateRootSnapshot GetLatestSnapshot <TAggregateRoot>(object aggregateID)
where TAggregateRoot : AggregateRoot
{
using (var connection = new SqlConnection(_connectionString))
{
var sql = string.Format(@"
Select Top 1 Type, Blob
From dbo.[{0}]
Where (AggregateID = @id)
And (AggregateType = @aType);", _tableName);
var command = new SqlCommand(sql, connection)
{
CommandType = CommandType.Text
};
command.Parameters.AddRange(new[] {
new SqlParameter {
ParameterName = "@id", SqlDbType = SqlDbType.NVarChar, Value = aggregateID
},
new SqlParameter {
ParameterName = "@aType", SqlDbType = SqlDbType.NVarChar, Value = typeof(TAggregateRoot).AssemblyQualifiedName
}
});
connection.Open();
using (var r = command.ExecuteReader())
{
var ordinal = new SnapshotOrdinal(r, false);
return(r.Read() ? MakeSnapshot(r, ordinal) : null);
}
}
}
/// <summary>
/// Gets the latest snapshots.
/// </summary>
/// <typeparam name="TAggregateRoot">The type of the aggregate root.</typeparam>
/// <param name="aggregateIDs">The aggregate I ds.</param>
/// <returns></returns>
public IEnumerable <AggregateTuple <AggregateRootSnapshot> > GetLatestSnapshots <TAggregateRoot>(IEnumerable <object> aggregateIDs)
where TAggregateRoot : AggregateRoot
{
var xml = new XElement("r", aggregateIDs
.Select(x => new XElement("s",
new XAttribute("i", x.ToString())))
);
using (var connection = new SqlConnection(_connectionString))
{
var sql = string.Format(@"
Select Type, Blob
From dbo.[{0}]
Inner Join @xml.nodes(N'/r/s') _xml(item)
On (AggregateID = _xml.item.value(N'@i', N'nvarchar(100)'))
And (AggregateType = @aType);", _tableName);
var command = new SqlCommand(sql, connection)
{
CommandType = CommandType.Text
};
command.Parameters.AddRange(new[] {
new SqlParameter {
ParameterName = "@aType", SqlDbType = SqlDbType.NVarChar, Value = typeof(TAggregateRoot).AssemblyQualifiedName
},
new SqlParameter {
ParameterName = "@xml", SqlDbType = SqlDbType.Xml, Value = xml.ToString()
}
});
connection.Open();
var snapshots = new List <AggregateTuple <AggregateRootSnapshot> >();
using (var r = command.ExecuteReader())
{
var ordinal = new SnapshotOrdinal(r, true);
while (r.Read())
{
snapshots.Add(MakeSnapshotTuple(r, ordinal));
}
}
return(snapshots);
}
}
private AggregateTuple <AggregateRootSnapshot> MakeSnapshotTuple(SqlDataReader r, SnapshotOrdinal ordinal)
{
var aggregateID = r.Field <string>(ordinal.AggregateID);
return(new AggregateTuple <AggregateRootSnapshot>
{
AggregateID = (_makeAggregateID == null ? aggregateID : _makeAggregateID(aggregateID)),
Item1 = MakeSnapshot(r, ordinal),
});
}
