Develop Reference

AWS .NET SDK DynamoDB Filter expression by Map values doesn't return any data

I'm trying to load data from DynamoDB.
I use FilterExpression and KeyExpression.
If I search by simple value on the top level everything works fine.
However, when I try to filter records by nested map values, I get 0 records.
CurrentCase is an object, Assignments is Dictionary, Setup is Enum.
Here is my code:
`Expression filterExpression = new ();
filterExpression.ExpressionAttributeNames["#Setup"] = "CurrentCase.Assignments.Setup";
filterExpression.ExpressionAttributeValues[":userId"] = userId;
filterExpression.ExpressionStatement = "#Setup = :userId";`
I tried another way, didn't help. (WHERE CurrentCase.Assignments['Setup'] = 'Id' works in PartyQL):
`Expression filterExpression = new ();
filterExpression.ExpressionAttributeNames["#Setup"] = "CurrentCase.Assignments['Setup']";
filterExpression.ExpressionAttributeValues[":userId"] = userId;
filterExpression.ExpressionStatement = "#Setup = :userId";`
This is how i call query
var queryOperationConfig = new QueryOperationConfig
{
PaginationToken = paginationToken,
Limit = pageSize,
IndexName = GlobalIndexNames.Cases,
KeyExpression = keyExpression,
FilterExpression = filterExpression
};
Search search = _dbContext.GetTargetTable<CaseEntity>().Query(queryOperationConfig);
List<Document> documents = await search.GetNextSetAsync(cancellationToken);
I expect that this request return all records where CurrentCase.Assignments['Setup'] equals userId

Forgive me, im not a .Net coder, but your issue is this:
filterExpression.ExpressionAttributeNames["#Setup"] = "CurrentCase.Assignments.Setup";
You are essentially setting your var #Setup to a String "CurrentCase.Assignments.Setup"
It should be:
ExpressionAttributeNames = new Dictionary<string, string>
{
{ "#CurrentCase", "CurrentCase" },
{ "#Assignments", "Assignments" },
{ "#Setup", "Setup" }
}
filterExpression.ExpressionStatement = "#CurrentCase.#Assignments#Setup = :userId";`
You may need to restructure the example I gave, but you should get the idea.

How can I use begins_with method on sort key using c# in DynamoDB

If I was to use the high level model, I might try something like this:
public async void GetBooksData()
{
GetItemRequest request = new GetItemRequest
{
TableName = "Customer",
Key = new Dictionary<string, AttributeValue>
{
{"UserName", new AttributeValue{S="a"} },
{"BookNum", new AttributeValue { S = starts_with(queryTerm)} }
}
};
try
{
var response = await client.GetItemAsync(request);
if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
{
if (response.Item.Count > 0)
{
foreach (var item in response.Item)
{
MessageBox.Show("Value : \n" + item.Value.S);
}
}
}
}
catch (InternalServerErrorException iee)
{
MessageBox.Show(iee);
}
}
I need to use the method 'begins_with' for getting 2 items what UserName is 'a' and the BookNum are book_1 and book_2. This is possible in the high level interface in Java. As an example as to what can be done on the range key in Java:
public List<Comment> allForItemWithMinRating(String itemId, int minRating) {
Comment comment = new Comment();
comment.setItemId(itemId);
Condition condition = new Condition()
.withComparisonOperator(ComparisonOperator.GE)
.withAttributeValueList(
new AttributeValue()
.withN(Integer.toString(minRating)));
DynamoDBQueryExpression<Comment> queryExpression
= new DynamoDBQueryExpression<Comment>()
.withHashKeyValues(comment)
.withRangeKeyCondition(
"rating",
condition
)
.withScanIndexForward(false);
return mapper.query(Comment.class, queryExpression);
}
In the low level interface for C# you can achieve this as so:
var requestDynamodb = new QueryRequest
{
TableName = "GroupEdEntries",
KeyConditionExpression = "partition_key = :s_Id and begins_with(sort_key, :sort)",
ExpressionAttributeValues = new Dictionary<string, AttributeValue> {
{":s_Id", new AttributeValue { S = my_id }},
{":sort", new AttributeValue { S = sort_key_starts_with }}
},
ConsistentRead = true
};
var results = await client.QueryAsync(requestDynamodb);
where the keys are called partition_key and sort_key. However, this returns the results as attribute values, which then need to be converted into POCOs one property at a time. It requires using reflection and is made more complicated using converters. It seems strange that this fundamental functionality (as well as other functionality) isn't supported in the C# SDK.
I ended up using reflection to create the tables based on the attributes, when this is also supported by default in Java. Am I missing a high level API for C#?

It's a bit of a different syntax and I can't find it documented anywhere (other than in code comments), but this works for me:
string partition_key = "123";
string sort_key_starts_with = "#type"
List<object> queryVal = new List<object>();
queryVal.Add(sort_key_starts_with);
var myQuery = context.QueryAsync<GroupEdEntry>(partition_key, QueryOperator.BeginsWith, queryVal);
var queryResult = await myQuery.GetRemainingAsync();

How to convert list to expandobject key in c#?

I have a function in which i am getting data(array of objects) from db and then adding those objects of array one by one into a lit of type ExpandoObject
public async Task<List<ExpandoObject>> GetGroupWithMaxTickets(){
List<ExpandoObject> topGroupsWithMaxTickets = new List<ExpandoObject>();
dynamic ticketDetails = new ExpandoObject();
var pipeline_tickets = new BsonDocument[]{
new BsonDocument("$match",
new BsonDocument
{
{ "nsp", "/sbtjapan.com" },
{ "datetime",
new BsonDocument
{
{ "$gte", "2019-12-03T00:00:34.417Z" },
{ "$lte", "2019-12-03T24:00:34.417Z" }
} }
}),
new BsonDocument("$group",
new BsonDocument
{
{ "_id", "$group" },
{ "totalTIckets",
new BsonDocument("$sum", 1) }
}),
new BsonDocument("$project",
new BsonDocument
{
{ "_id", 0 },
{ "group", "$_id" },
{ "totalTIckets", 1 }
}),
new BsonDocument("$sort",
new BsonDocument("totalTIckets", -1)),
new BsonDocument("$limit", 5)
};
var collection = await DbService.tickets.AggregateAsync<RawBsonDocument>(pipeline_tickets, new AggregateOptions {UseCursor = true, BatchSize = 500});
await collection.MoveNextAsync();
if(collection.Current.ToList().Count > 0){
// ticketDetails = JsonConvert.DeserializeObject(collection.Current.ToJson());
// ticketDetails.group = collection.Current.ToList()[0]["group"];
// ticketDetails.totalTickets = collection.Current.ToList()[0]["totalTIckets"];
Parallel.ForEach(collection.Current.ToList(), (ticket) => {
Console.WriteLine("Ticket----"+ticket);
dynamic groupWithTickets = new ExpandoObject();
groupWithTickets = ticket;
topGroupsWithMaxTickets.Add(groupWithTickets);
});
}
return topGroupsWithMaxTickets;
}
But it throws an error like this
System.AggregateException: One or more errors occurred. (The best overloaded method match for 'System.Collections.Generic.List<System.Dynamic.ExpandoObject>.Add(System.Dynamic.ExpandoObject)' has some invalid arguments)
I want that my function must return array of objects of type List<ExpandoObject>
How can i do this in c#?

Since you have changed the question, following is the answer that should resolve your matters.
How to NOT work with ExpandoObjects
I tested this on my system and got it to reproduce the same results as you are getting. Following is the failed try:
dynamic employee = new ExpandoObject();
List<ExpandoObject> listOfEmployees = new List<ExpandoObject>();
employee = "someStrangeString";
listOfEmployees.Add(employee); // ERROR !!!!
and just as expected, i get the following error on Add.
Microsoft.CSharp.RuntimeBinder.RuntimeBinderException
HResult=0x80131500
Message=The best overloaded method match for 'System.Collections.Generic.List.Add(System.Dynamic.ExpandoObject)' has some invalid arguments
Source=
StackTrace:
Corrected way of ExpandoObject use
Following is the method that will take care of the issues with Adding it to the list.
Parallel.ForEach(collection.Current.ToList(), (ticket) =>
{
Console.WriteLine("Ticket----" + ticket);
dynamic groupWithTickets = new ExpandoObject();
groupWithTickets.users = ticket; //<---- Assign ticket to users element.
topGroupsWithMaxTickets.Add(groupWithTickets);
});
What was done to fix it?
When you are working with ExpandoObjects, you have to think of dictionary type of a deal. When you declare ExpandoObject, you have to dynamically assign the value to an element (that you define).
Example from MS site: shows the proper use of ExpandoObject
dynamic employee, manager;
employee = new ExpandoObject();
employee.Name = "John Smith";
employee.Age = 33;
manager = new ExpandoObject();
manager.Name = "Allison Brown";
manager.Age = 42;
manager.TeamSize = 10;
Hopefully this resolves your issue.

It should be like this;
dynamic ticketDetails = new ExpandoObject();
ticketDetails.user = collection;
string json = Newtonsoft.Json.JsonConvert.SerializeObject(ticketDetails);

You can simply do this:
dynamic ticketDetails = new ExpandoObject();
ticketDetails = Json(new users = JsonConvert.DeserializeObject(collection.Current.ToJson()));

For testing purposes, i used an array arr that holds one of the elements. If you need that array to be part of ExtendoObject with first element being users, you can create a Json object and set the array as value to the "users" element.
dynamic ticketDetails = new ExpandoObject();
JArray arr = new JArray();
arr.Add(#"[{""name"": ""Alex"", ""age"": 21}]");
JObject o = new JObject();
o["users"] = arr.ToString();
ticketDetails = o;
// output: { "users" : [{"name" : "Alex", "age" : 21}]}

how to form comma separated string from bson array using asp.net core 2.2?

I have an api based on asp.net core 2.2 in which i am building up an array of ips(strings type) like this
[HttpGet ("{nsp}/geolocation")]
[ResponseCache (Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
public async Task<dynamic> getLocation (string nsp) {
nsp = "/"+nsp;
// string ipInfoBaseUrl = "http://ip-api.com/json/";
string baseUrl = "http://ip-api.com/batch";
// string userIpAddress = "197.157.194.90";
// string ipUrl = ipInfoBaseUrl + userIpAddress;
// var client = _httpClientFactory.CreateClient();
// var result = await client.PostAsync(baseUrl,new StringContent(JsonConvert.SerializeObject(finals), System.Text.Encoding.UTF8, "application/json"));
// // var final = Newtonsoft.Json.JsonConvert.DeserializeObject<UserLocation>(result);
// Console.WriteLine(finals+" --result-----");
// return Ok(result);
var match = new BsonDocument ();
var group = new BsonDocument ();
var project = new BsonDocument ();
var sort = new BsonDocument ();
var addFields = new BsonDocument ();
var pipeline = new [] { new BsonDocument () };
/* #Aggregation : Stage-1 */
match = new BsonDocument ("$match",
new BsonDocument {
{
"nsp" , nsp
}
});
/* #Aggregation : Stage-2 */
group = new BsonDocument("$group",
new BsonDocument
{ {
"_id", "null"
},
{ "geoLocations",
new BsonDocument("$addToSet", "$visitor.ip")
}
});
/* #Aggregation : Stage-3 */
project = new BsonDocument ("$project", new BsonDocument { { "_id", 0 }});
pipeline = new [] { match, group,project};
var list = await DbService.tickets.AggregateAsync<BsonDocument> (pipeline, new AggregateOptions { UseCursor = true, BatchSize = batchCount });
while (await list.MoveNextAsync ()) {
var list_real = new List<BsonValue> ();
foreach (var data in list.Current.ToArray ()) {
list_real.Add (data);
}
return list_real.ToJson ();
}
return new BsonArray ().ToJson ();
}
It is returning result like this
[
{
" geoLocations": [
"122.8.208.9",
"196.62.107.243",
"182.188.38.219",
"39.50.244.198",
"39.51.40.251",
"103.20.134.56",
"103.228.156.83",
"202.143.125.21",
"196.62.151.47",
"45.116.232.50",
"39.57.128.75",
"103.18.8.60",
"202.143.125.20",
"182.190.252.96",
"119.153.56.2",
"46.101.89.227",
"196.194.172.211",
"192.168.20.186",
"64.233.173.146",
"104.236.195.147",
"39.50.156.242",
"103.255.5.58"
]
}
]
How can i get comma separated string from this result like
"111.92.158.82","202.142.168.162","122.8.157.172",.....
From very first i am getting all ips from all documents from my collection and forming an array of ips.But my ultimate goal is to form a comma separated string from that array because i have to pass that comma separated string of ips into an api to get ips locations.
I am using asp.net core and c#. How can i achieve this?

Assuming you want a single comma-separated result string containing all IP addresses, replace the method signature with IEnumerable<string>, and replace the bottom of the method with. Just use whatever you need for your result and get rid of the rest.
var list = await DbService.tickets.AggregateAsync<BsonDocument> (pipeline,
new AggregateOptions
{
UseCursor = true,
BatchSize = batchCount
});
var result = new List<string>();
while (await list.MoveNextAsync())
result.AddRange(list.Current.Cast<string>());
return string.Join(',', result);
I'm not sure why you're doing everything with BsonDocuments, you can just iterate over the data directly and return strings.
Also, consider upgrading to .NET Core 3, which you can then use C# 8's async enumerable. You'll also be able to use the new JSON functionality built-in .NET Core 3.
This will return:
"122.8.208.9,196.62.107.243,182.188.38.219,<all the rest>"

How to execute ActivityBuilder without serializing it?

Let's say I have a workflow created progrmatically like this
ActivityBuilder<int> ab = new ActivityBuilder<int>();
ab.Name = "Add";
ab.Properties.Add(new DynamicActivityProperty {Name = "Operand1", Type = typeof (InArgument<int>)});
ab.Properties.Add(new DynamicActivityProperty {Name = "Operand2", Type = typeof (InArgument<int>)});
ab.Implementation = new Sequence
{
Activities =
{
new WriteLine
{
Text =
new VisualBasicValue<string>(
"Operand1.ToString() + \" + \" + Operand2.ToString()")
}
}
};
One way I know to execute it is to first serialize the ActivityBuilder object into XAML. Next, load the serialized XAML using ActivityXamlServices. Create a dictionary for parameters. Execute it using WorkflowInvoker or WorkflowApplication
Is there any way to execute this workflow without the need to convert/serialize activity builder to XAML?
WorkflowApplication and WorkflowInvoker takes an Activity as input for execution. Can I somehow use activityBuilder.Implementation directly with WorkflowApplication or WorkflowInvoker?
Why I want this? Because we have a workflow designer which user uses to create and execute workflow. User also creates workflow progrmatically. Workflow can be up to 80MB in size. This is hurting application's memory due to serialization and de-serialization of 80MB files to and from XAML. I want to somehow skip this step and directly execute activity.
Does it makes sense?

No need to use an ActivityBuilder, just create the activities you want and execute them.
var wf = new Sequence()
{
Variables =
{
new Variable<int>("Operand1", 7),
new Variable<int>("Operand2", 42)
},
Activities =
{
new WriteLine
{
Text =
new VisualBasicValue<string>(
"Operand1 & \" + \" & Operand2")
}
}
};
WorkflowInvoker.Invoke(wf);
An example using DynamicActivityProperty:
var wf = new DynamicActivity<int>
{
Properties =
{
new DynamicActivityProperty { Name = "Operand1", Type = typeof(InArgument<int>) },
new DynamicActivityProperty { Name = "Operand2", Type = typeof(InArgument<int>) }
},
Implementation = () => new Sequence()
{
Activities =
{
new WriteLine
{
Text =
new VisualBasicValue<string>(
"Operand1 & \" + \" & Operand2")
},
new Assign<int>
{
To = new ArgumentReference<int> { ArgumentName = "Result" },
Value = new VisualBasicValue<int>("Operand1 + Operand2")
}
}
}
};
var inputs = new Dictionary<string, object>();
inputs["Operand1"] = 7;
inputs["Operand2"] = 42;
var output = WorkflowInvoker.Invoke(wf, inputs);
Console.WriteLine(output);