我有一个带有独立 BsonClass 映射的 C# 类层次结构。我所有的类(class)都使用自定义顺序 int id 生成。 Last Id 存储在名为“Counter”的特殊集合中。我的问题是当 InsertOneAsync 之类的 mongo 集合方法被称为 InvalidCastException 时被抛出。
基础实体类:
[Serializable]
public abstract class Entity<TIdentifier> : IEntity<TIdentifier>
{
public TIdentifier Id { get; set; }
public DateTime CreatedDate { get; set; }
public DateTime UpdatedDate { get; set; }
public virtual bool IsTransient()
{
return (object) this.Id == null || this.Id.Equals((object) default (TIdentifier));
}
}
子类:
public class Child : Entity<int>
{
public int SomeData { get; set; }
}
基类图:
public class EntityMap
{
public static void Register()
{
BsonClassMap.RegisterClassMap<Entity<int>>(cm =>
{
cm.AutoMap();
cm.MapIdProperty(c => c.Id)
.SetIdGenerator(SeqIntIdGenerator<Entity<int>>.Instance)
.SetSerializer(new Int32Serializer(BsonType.Int32));
});
}
}
子类图:
public class ChildMap
{
public static void Register()
{
BsonClassMap.RegisterClassMap<Child>(cm =>
{
cm.AutoMap();
cm.SetIgnoreExtraElements(true);
});
}
}
顺序 int id 生成器类:
public class SeqIntIdGenerator<TEntity> : IIdGenerator
{
public static SeqIntIdGenerator<TEntity> Instance { get; } = new SeqIntIdGenerator<TEntity>();
public object GenerateId(object container, object document)
{
//InvalidCastException thrown here on InsertOneAsync!!!
var idSequenceCollection = ((IMongoCollection<TEntity>)container).Database.GetCollection<dynamic>("Counters");
var filter = Builders<dynamic>.Filter.Eq("_id", ((IMongoCollection<TEntity>)container).CollectionNamespace.CollectionName);
var update = Builders<dynamic>.Update.Inc("Seq", 1);
var options = new FindOneAndUpdateOptions<dynamic>
{
IsUpsert = true,
ReturnDocument = ReturnDocument.After
};
return idSequenceCollection.FindOneAndUpdate(filter, update, options).Seq;
}
public bool IsEmpty(object id)
{
return (int)id == 0;
}
}
将容器从 Object 转换为 IMongoCollection 时抛出 InvalidCastException>。怎么做才对?我的 C# 驱动程序版本是 2.7.2。
最佳答案
如果您已经在使用动态,则可以为此关闭反射
public object GenerateId(object container, object document)
{
var containerDynamic = (dynamic) container;
var idSequenceCollection = containerDynamic.Database.GetCollection<dynamic>("Counters");
var filter = Builders<dynamic>.Filter.Eq("_id", containerDynamic.CollectionNamespace.CollectionName);
var update = Builders<dynamic>.Update.Inc("Seq", 1);
var options = new FindOneAndUpdateOptions<dynamic>
{
IsUpsert = true,
ReturnDocument = ReturnDocument.After
};
return idSequenceCollection.FindOneAndUpdate(filter, update, options).Seq;
}
关于c# - 用于 C# 类层次结构的 MongoDb 顺序 int id 生成器,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54404419/