Develop Reference

Sub Document operations in couchbase using .net sdk

Delete a specific node from all the available documents in a bucket
Is it possible to delete an element from the children array based on the Id from the below sample document using .NET SDK for Couchbase in C#?
i.e. I need to delete all the details of Id=100( delete the entire element in the children array).
I can achieve it using N1QL. N1QL performance is slow when there are thousands of document involved in couchbase
{
"results": [{
"tutorial": {
"type": "contact",
"title": "Mr.",
"fname": "Ian",
"lname": "Taylor",
"age": 56,
"email": "ian#gmail.com",
"children": [{
"Id": "100",
"Details": [{
"fname": "Abama",
"age": 17,
"gender": "F"
}]
},
{
"Id": "101",
"Details": [{
"fname": "Alex",
"age": 17,
"gender": "M"
}]
}
],
"hobbies": [
"golf",
"surfing"
],
"relation": "cousin"
}
}]
}

How can I push an array into aggregate pipeline and pull it one level up?

I am new in MongoDB and I am developing a software by C# and MongoDB. My data structure is like this
{
"Id": 1,
"Title": "myTitle",
"Geners": [ "Drama", "Action" ],
"Category": 1,
"Casts": [
{
"Id": 1,
"Name": "myName",
"Gender": "Male",
"Age": 35
},
{
"Id": 2,
"Name": "herName",
"Gender": "Female",
"Age": 30
},
{
"Id": 3,
"Name": "hisName",
"Gender": "Male",
"Age": 45
}
]
}
This is just one document and I have about 5 million documents. I want to run a query like below to count the records based on Category and shows me how many movie do I have in each category and I want to put Casts field in result.
db.getCollection('myCollection').aggregate([
{
$group:{"_id":"$Category", "count": {$sum:1},
"Casts":{$push:"$Casts"}}
}
])
this is close to something I want but the problem is, it puts Casts data in second level of array like {"Id":1, ... , "Casts":[[{},{},...]]} but I need it like this {"Id":1, ... , "Casts":[{},{},...]}
How can I show the data like that?

If duplicates are acceptable, then the following aggregation will suffice:
db.getCollection('myCollection').aggregate([
{ $unwind:"$Casts"},
{
$group:{"_id":"$Category", "count": {$sum:1},
"Casts":{$push:"$Casts"}}
}
])
Update:
Since you need the count to be valid, there's a few more hoops to jump through.
db.getCollection('myCollection').aggregate([
{ $group:{"_id":"$Category", "count": {$sum:1}, "Casts":{$addToSet:"$Casts"}}},
{$unwind:"$Casts"},
{$unwind:"$Casts"},
{ $group:{"_id":"$_id", "count": {$first:"$count"}, "Casts":{$addToSet:"$Casts"}}},
])
Let me know if that helps

Unexpected JSON token when reading DataTable. Expected StartArray, got StartObject

I have a valid json (any json string) string and trying to convert it to Dataset but Newtonsoft.Json failed to do so.
Json text:
{"root": {
"Item": [
{
"Name": "Super Mario Bros",
"Count": "14",
"Price": "29,99",
"Comment": "-No Comment-",
"Artist": "N/A",
"Publisher": "Nintendo",
"Genre": "Video Games",
"Year": "1985",
"ProductID": "001"
},
{
"Name": "The Legend of Zelda",
"Count": "12",
"Price": "34,99",
"Comment": "-No Comment-",
"Artist": "N/A",
"Publisher": "Nintendo",
"Genre": "Video Games",
"Year": "1986",
"ProductID": "002"
}
]
}
}
Code:
var table = JsonConvert.DeserializeObject<DataSet>(jsonText);
Error:
Unexpected JSON token when reading DataTable. Expected StartArray, got StartObject. Path 'root', line 1, position 9.
Edit 1:
user can pass any type of json and i need to convert it to DataSet
for the above example "root" element can contain any other property
like "child1":"val1", "child2":"val2" and so forth. so, the output
dataset will contain 2 tables namse root(should have one rows of
properties 1 and 2) and item(should have 2 rows of type name,count,price
etc).

It is not working because the JSON object representing the DataSet is not at the root level of the JSON. In your JSON, it is inside a property called root, which is inside another wrapper object. So you will need to take that outer object into account when you deserialize. You can either define a wrapper class and deserialize into that:
public class Wrapper
{
[JsonProperty("root")]
public DataSet DataSet { get; set; }
}
Then:
DataSet ds = JsonConvert.DeserializeObject<Wrapper>(json).DataSet;
(Fiddle)
Or, if you don't want to make a class, you can instead deserialize into a JObject, navigate down to the root property and then materialize it to a DataSet from there:
DataSet ds = JObject.Parse(json)["root"].ToObject<DataSet>();
(Fiddle)

The Json you showed is invalid.
It should look like this, to be load to the DataSet:
{
"Item": [
{
"Name": "Super Mario Bros",
"Count": "14",
"Price": "29,99",
"Comment": "-No Comment-",
"Artist": "N/A",
"Publisher": "Nintendo",
"Genre": "Video Games",
"Year": "1985",
"ProductID": "001"
},
{
"Name": "The Legend of Zelda",
"Count": "12",
"Price": "34,99",
"Comment": "-No Comment-",
"Artist": "N/A",
"Publisher": "Nintendo",
"Genre": "Video Games",
"Year": "1986",
"ProductID": "002"
}
]
}
Code:
var dataSet = JsonConvert.DeserializeObject<DataSet>(jsonText);
var table = dataSet.Tables[0];

just add [] while stringifying the object:
JSON.stringify([this.YourModel])

C# Newtsonsoft.Json - Deserialize JSON with nested arrays to DataTable

I have JSON data with nested arrays (see example below). What I am trying to accomplish is to deserialize this data into a DataSet where each nested array gets inserted into a corresponding datatable.
Example:
[
{
"Id": "1",
"LastName": "John",
"FirstName": "Doe",
"MiddleInitial": "I",
"DateOfBirth": "2000-10-05",
"Gender": "M",
"LastModifiedDate": "2017-03-13 14:36:53",
"Classes": [
{
"ClassNumber": "21",
"TeacherID": "15"
},
{
"ClassNumber": "12",
"TeacherID": "10"
}
]
},
{
"Id": "2",
"LastName": "Jane",
"FirstName": "Doe",
"MiddleInitial": "K",
"DateOfBirth": "2000-10-05",
"Gender": "F",
"LastModifiedDate": "2017-03-13 14:36:53",
"Classes": [
{
"ClassNumber": "11",
"TeacherID": "8"
},
{
"ClassNumber": "4",
"TeacherID": "26"
}
]
}]
So the dataset would contain 2 datatables. One with all of the records from the main array and the second with all of the records from the "Classes" array.

You kind of have to create the DataSet and its DataTables manually and fill them manually. There's no automatic way of doing it, if that's what you were hoping for. If you need to maintain the relationships between the objects you have to add a foreign key to the Class anyway, otherwise there's no way to know which person a Class belongs to.
The table columns could be generated from the JSON properties, of course, if you're careful enough with how you write the code or if the JSON structure is always the same without exception.

Deserialize Dynamic Json string using Newtonsoft JSON.NET

I have a JSON string that I'm getting from Facebook API, in which I have a node whose name changes according to its content, for example some time it is 45, or 58 etc.
It could be any number.
I want its value. How to get it?
Example:
{
"data": [
{
"id": "1492292372_10201810786059989",
"created_time": "2014-04-05T09:00:54+0000"
},
{
"id": "1492292372_10201804679827337",
"created_time": "2014-04-04T07:29:07+0000"
},
{
"id": "1492292372_10201804649306574",
"created_time": "2014-04-04T07:10:33+0000"
},
{
"id": "1492292372_10201801316823264",
"created_time": "2014-04-03T18:31:50+0000"
},
{
"id": "1492292372_10201798962284402",
"created_time": "2014-04-03T06:24:47+0000"
},
{
"message_tags": {
"0": [
{
"id": "1492292372",
"name": "Yawar Sohail",
"type": "user",
"offset": 0,
"length": 12
}
],
"15": [
{
"id": "1489845168",
"name": "Zeeshan Anjum",
"type": "user",
"offset": 15,
"length": 13
}
]
},
"id": "1492292372_10201796274777216",
"created_time": "2014-04-02T17:57:05+0000"
},
{
"id": "1492292372_10201794080482360",
"created_time": "2014-04-02T07:26:23+0000"
},
Inside message_tags there are two nodes [0 and 15] they dynamically changes according to their offset values. I want names, type and ids inside these nodes.

You can deserialize your JSON into an ExpandoObject:
var converter = new ExpandoObjectConverter();
dynamic obj = JsonConvert.DeserializeObject<ExpandoObject>(json, converter);
Which dynamically adds members to your object at runtime, and allows you to iterate over them as described in this answer:
foreach (var prop in obj.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public))
{
Console.WriteLine("Name: {0}, Value: {1}",prop.Name, prop.GetValue(obj,null));
}
That way you can iterate over obj.message_tags to get the individual messages, and obtain all their details respectively.