MangoDB在C#中的使用

时间：2019-12-06 16:26:36 阅读：177 评论：0 收藏：0 [点我收藏+]

https://mongodb-documentation.readthedocs.org/en/latest/ecosystem/tutorial/serialize-documents-with-the-csharp-driver.html Serialize Documents with the CSharp Driver(使用c#对实体进行序列化)

https://www.mongodb.com/thank-you/download/mongodb-enterprise 官网下载地址

http://www.ttlsa.com/mms/follow-me-to-use-mongodb-mms-services/ 随我来使用mongodb mms服务

当类体结构改变，删除了某个属性，或者某个属性的类型发生了改变？

1、属性的类型发生了改变

  1 public class Address { public ObjectId Id; public string ZipCode; }
  2 
  3 public class ZipCodeSerializer : BsonBaseSerializer { public override object Deserialize(BsonReader bsonReader, Type nominalType, Type actualType, IBsonSerializationOptions options) { var bsonType = bsonReader.CurrentBsonType; switch (bsonType) { case BsonType.Null: bsonReader.ReadNull(); return null; case BsonType.String: return bsonReader.ReadString(); case BsonType.Int32: return bsonReader.ReadInt32().ToString(); default: var message = string.Format("ZipCodeSerializer expects to find a String or an Int32, not a {0}.", bsonType); throw new BsonSerializationException(message); } } public override void Serialize(BsonWriter bsonWriter, Type nominalType, object value, IBsonSerializationOptions options) { if (value == null) { bsonWriter.WriteNull(); } else { bsonWriter.WriteString((string)value); } } }
  4 
  5 BsonClassMap.RegisterClassMap<Address>(cm => { cm.AutoMap(); cm.GetMemberMap(a => a.ZipCode).SetSerializer(new ZipCodeSerializer()); });
  6

View Code

2、删除了某个属性

  1 var allDocuments = collectionToUpdate .FindAll();foreach(var document in allDocuments ){var oldFieldValue = document ["OldFieldName"];if(!document.Contains("NewFieldName")) document.Add("NewFieldName", oldFieldValue); document.Remove("OldFieldName"); collectionToUpdate.Save(document);}
  2 
  3 3、使用newtonsoft.json转换为json
  4 
  5 class ObjectId Converter:JsonConverter{publicoverridevoidWriteJson(JsonWriter writer,object value,JsonSerializer serializer){ serializer.Serialize(writer, value.ToString());}publicoverrideobjectReadJson(JsonReader reader,Type objectType,object existingValue,JsonSerializer serializer){thrownewNotImplementedException();}publicoverride bool CanConvert(Type objectType){returntypeof(ObjectId).IsAssignableFrom(objectType);//return true;}}
  6 
  7         public class ObjectIdConverter : TypeConverter
  8 
  9         {
 10 
 11             public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
 12 
 13             {
 14 
 15                 if (sourceType == typeof(string))
 16 
 17                 {
 18 
 19                     return true;
 20 
 21                 }
 22 
 23                 return base.CanConvertFrom(context, sourceType);
 24 
 25             }
 26 
 27             public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
 28 
 29             {
 30 
 31                 if (value is string)
 32 
 33                     return ObjectId.Parse((string)value);
 34 
 35                 return base.ConvertFrom(context, culture, value);
 36 
 37             }
 38 
 39             // Overrides the ConvertTo method of TypeConverter.
 40 
 41             public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
 42 
 43             {
 44 
 45                 if (destinationType == typeof(string))
 46 
 47                 {
 48 
 49                     return ((ObjectId)value).ToString();
 50 
 51                 }
 52 
 53                 return base.ConvertTo(context, culture, value, destinationType);
 54 
 55             }
 56 
 57         }
 58