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[英]mongodb C# exception Cannot deserialize string from BsonType Int32
[英]C# Mongo Driver error: Cannot deserialize a 'Int32' from BsonType 'Document'
以下MongoDB查詢在Robo3T 1.2上運行良好,並返回正確的“計數”。
db.runCommand( {
aggregate: "User",
pipeline: [
{$unwind: '$UserSubscriptions'},
{$group: {
_id: '$_id',
codes: {$addToSet: '$UserSubscriptions.Subscription.Publication'}
}},
{$unwind: '$codes'},
{$group: {
_id: '$codes',
count: {$sum: 1}
}}
]
} )
我正在嘗試將上述查詢轉換為C#MongoDriver查詢
var unwind = new BsonDocument { { "$unwind", "$UserSubscriptions" } };
var group1 = new BsonDocument
{
{ "$group",
new BsonDocument
{
{ "_id", new BsonDocument
{
{
"Id","$_id"
}
}
},
{
"codes", new BsonDocument
{
{
"$addToSet","$UserSubscriptions.Subscription.Publication.Code"
}
}
}
}
}
};
var unwindCode = new BsonDocument { { "$unwind", "$codes" } };
var group2 = new BsonDocument
{
{ "$group",
new BsonDocument
{
{ "_id", new BsonDocument
{
{
"Id","$codes"
}
}
},
{
"codes", new BsonDocument
{
{
"$sum",1
}
}
}
}
}
};
var pipeline = new[] { unwind, group1 , unwindCode , group2 };
var result = coll.Aggregate<T>(pipeline);
但是出現錯誤無法從BsonType'Document'反序列化'Int32'。
ID是集合中的主鍵
public int ID {get; 組; }
請告知如何實現此目標。
(機器人3T 1.2.1)(MongoDB.Driver 2.4.4)
您正在嘗試通過為“ _id”創建BsonDocument將BsonDocument反序列化為“ Int32”。 您只需要這樣做:
var group1 = new BsonDocument
{
{
"$group", new BsonDocument
{
{
"_id", "$_id"
},
{
"codes", new BsonDocument
{
{
"$addToSet", "$UserSubscriptions.Subscription.Publication.Code"
}
}
}
}
}
};
var group2 = new BsonDocument
{
{
"$group", new BsonDocument
{
{
"_id", "$codes"
},
{
"count", new BsonDocument
{
{
"$sum", 1
}
}
}
}
}
};
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