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How can I achieve DynamoDB Pagination Same as SQL/MYSQL(Total count of items and I can jump to any other page) in C#

how to implement pagination using DynamoDB in c# same as SQL/MYSQL.
I have check document for ScanRequest and QueryRequest that one is working perfectly fine.
But I need Pagination same as we all do in SQL/MYSQL like in initial call I need total number of item count and page wise records and easily I can jump to any other page also.
So anyone can suggest good solution or any alternative solution?
Thank you in advance.
Dictionary<string, AttributeValue> lastKeyEvaluated = null;
do
{
var request = new ScanRequest
{
TableName = "Test",
Limit = 5,
ExclusiveStartKey = lastKeyEvaluated
};
var response = await Client.ScanAsync(request);
lastKeyEvaluated = response.LastEvaluatedKey;
}
while (lastKeyEvaluated.Count != 0);
Dictionary<string, Condition> conditions = new Dictionary<string, Condition>();
// Title attribute should contain the string "Adventures"
Condition titleCondition = new Condition();
titleCondition.ComparisonOperator = ComparisonOperator.EQ;
titleCondition.AttributeValueList.Add(new AttributeValue { S = "Company#04" });
conditions["PK"] = titleCondition;
var request = new QueryRequest();
request.Limit = 2;
request.ExclusiveStartKey = null;
request.TableName = "Test";
request.KeyConditions = conditions;
var result = await Client.QueryAsync(request);

DynamoDB supports an entirely different type of pagination. The concept of page number, offset, etc. is another paradigm from the SQL database world that has no parallel in DynamoDB. However, pagination is supported, just not the way many expect.
You may want to consider changing how your client application paginates to accommodate. If you have a small amount of information to paginate (e.g. under 1MB of data), you might consider passing it to the client and letting the client implement the pagination (e.g. page 4 of 15).
If you have too much data to paginate client-side, you may want to consider updating your client application to accommodate how DynamoDB paginates (e.g. using LastEvaluatedKey and ExclusiveStartKey).

Find within large list using Contains within Linq

I have two large excel files. I am able to get the rows of these excel files into a list using linqtoexcel. The issue is that I need to use a string from one object within the first list to find if it is part of or contained inside another string within an object of the second list. I was trying the following but the process is taking to long as each list is over 70,000 items.
I have tried using an Any statement but have not be able to pull results. If you have any ideas please share.
List<ExcelOne> exOne = new List<ExcelOne>();
List<ExcelTwo> exTwo = new List<ExcelTwo>();
I am able to build the first list and second list and can verify there are objects in the list. Here was my thought of how I would work through the lists to find matching. Note that once I have found the matching I want to create a new class and add it to a new list.
List<NewFormRow> rows = new List<NewFormRow>();
foreach (var item in exOne)
{
//I am going through each item in list one
foreach (var thing in exTwo)
{
//I now want to check if exTwo.importantRow has or
//contains any part of the string from item.id
if (thing.importantRow.Contains(item.id))
{
NewFormRow adding = new NewFormRow()
{
Idfound = item.id,
ImportantRow = thing.importantRow
};
rows.Add(adding);
Console.WriteLine("added one");
}
}
If you know a quicker way around this please share. Thank you.

It's hard to improve this substring approach. The question is if you have to do it here. Can't you do it where you have filled the lists? Then you don't need this additional step.
However, maybe you find this LINQ query more readable:
List<NewFormRow> rows = exOne
.SelectMany(x => exTwo
.Where(x2 => x2.importantRow.Contains(x.id))
.Select(x2 => new NewFormRow
{
Idfound = x.id,
ImportantRow = x2.importantRow
}))
.ToList();

Using the Rally REST API, how to query and return a *complete* JSON object?

I'm using the .NET API. By complete, I mean a JSON like this one (formatted already, I think it is needed credentials to see it inside the webservice).
It is just a matter of adding more fields to fetch when I instantiate the Request object?
Request storyRequest = new Request("hierarchicalrequirement")
{
/* Fields to Fetch*/
Fetch = new List<string>() { "Name", "FormattedID", "Children", "Owner", "ScheduleState" },
// keep adding field here...
/* Add a query - quering the US with ID equals to '_formattedID'*/
Query = new Query("FormattedID", Query.Operator.Equals, _formattedID)
};
Thanks in advance!
EDIT
I would like to query by the user story ID, just in case it is not clear.

When building a request, you should filter the field you want to fetch in the Fetch property.
The keys:
_rallyAPIMajor
_rallyAPIMinor
_ref
_objectVersion
_refObjectName
Are always return by any request. You can leave the Fetch empty, and return all 45 keys (45 for "hierarchicalrequirement") or you can filter the ones you need.

Querying 2 datatables in a dataset

I have 2 datatables named 'dst' and 'dst2'. they are located in the dataset 'urenmat'.
The mayority of the data is in 'dst'. this however contains a column named 'werknemer'. It contains a value which corresponds to a certain row in 'dst2'. This column is named 'nummer'.
What i need is a way to left outer join both datatables where dst.werknemer and dst2.nummer are linked, and a new datatable is created which contains 'dst2.naam' linked to 'dst.werknemer' along with all the other columns from 'dst'.
I have looked everywhere and still can't seem te find the right answer to my question. several sites provide a way using LINQ in this situation. I have tried using LINQ but i am not so skilled at this.
I tried using the 101 LINQ Samples:
http://code.msdn.microsoft.com/101-LINQ-Samples-3fb9811b
urenmat = dataset.
dst = a, b, c, d, werknemer.
dst2 = nummer, naam.
I used the following code from '101'.
var query =
from contact in dst.AsEnumerable()
join order in dst2.AsEnumerable()
on contact.Field<string>("werknemer") equals
order.Field<string>("nummer")
select new
{
a = order.Field<string>("a"),
b = order.Field<string>("b"),
c = order.Field<string>("c"),
d = order.Field<string>("d"),
naam = contact.Field<decimal>("naam")};
I however don't know what to change 'contact' and 'order' to and i can't seem to find out how to save it to a datatable again.
I am very sorry if these are stupid questions but i have tried to solve it myself but it appears i'm stupid:P. Thank for the help in advance!
PS. i am using C# to code, the dataset and datatables are typed.

if you want to produce a projected dataset of dst left outer joined to dst2 you can use this LINQ expression (sorry i don't really work in LINQ query syntax so you'll have to use this lambda syntax instead).
var query = dst.AsEnumerable()
.GroupJoin(dst2.AsEnumerable(), x => x.Field<string>("werknemer"), x => x.Field<string>("nummer"), (contact, orders) => new { contact, orders })
.SelectMany(x => x.orders.DefaultIfEmpty(), (x, order) => new
{
a = order.Field<string>("a"),
b = order.Field<string>("b"),
c = order.Field<string>("c"),
d = order.Field<string>("d"),
naam = x.contact.Field<decimal>("naam")
});
because this is a projected dataset you cannot simply save back to the datatable. If saving is desired then you would want to load the affected row, update the desired fields, then save the changes.
// untyped
var row = dst.Rows.Find(keyValue);
// typed
var row = dst.FindBy...(keyValue);
// update the field
row.SetField("a", "some value");
// save only this row's changes
row.AcceptChanges();
// or after all changes to the table have been made, save the table
dst.AcceptChanges();
Normally if you need to perform loading and saving of (projected) data, an ORM (like entity framework, or LINQ-to-SQL) would be the best tool. However, you are using DataTable's in this case and I'm not sure if you can link an ORM to these (though it seems like it would probably be possible).

How to filter on multiple SubItems in ObjectListView

So, I am trying to programmatically add in a ModelFilter to my ObjectListView that will look at two (or more) columns and filters on each separately. Currently, I think that ObjectListView only supports one filter, but I may be missing something in the code/documentation.
As an example, one of my intended filters is to look at column "Active" and that has values of "A" or "T". Another column is a Supervisor Name. So, I want to find all entries where Supervisor name = "Smith" and Active = "A".
I can get the filter to work for either of these options separately using TextMatchFilter, but cannot figure out how to get both to work at the same time.
The minor problem I see is that if the Supervisor Name contains an "A", then using the standard Filter will return the whole row. I have been able to get around that by programmatically setting the Searchable property for columns to false if I don't want to look at them, and then turn them back on once the list is filtered. However, I have a feeling that if I turn Searchable on for the Supervisor column, I will get the unwanted results.
Does anyone know of a way to get the filter to work on multiple columns, using only the indicated columns for each filter?
(I have no sample code to show that helps in solving this. However, if you really want to see what I have for my filtering code, I will be happy to add that; it is in VB however).
Current Code - This looks at a value chosen by the user (searchMeth) and enables searching on that column. It then does the search for what was entered in the txtSearch box. However, in addition to this, I want to add in an additional filter for Supervisor. (See the AndAlso comment
olvEmps.UseFiltering = True
OlvColumn1.Searchable = False
OlvColumn2.Searchable = False
OlvColumn4.Searchable = False
OlvColumn3.Searchable = False
OlvColumn5.Searchable = False
Select Case searchMeth
Case "Name"
OlvColumn1.Searchable = True
Case "Employee Number"
OlvColumn2.Searchable = True
Case "Department"
OlvColumn3.Searchable = True
End Select
olvEmps.OwnerDraw = True
Dim tFilter As BrightIdeasSoftware.TextMatchFilter = BrightIdeasSoftware.TextMatchFilter.Contains(olvEmps, txtSearch.Text)
'andalso olvColumn5 = supeName?
olvEmps.ModelFilter = tFilter
olvEmps.DefaultRenderer = New BrightIdeasSoftware.HighlightTextRenderer(tFilter)
OlvColumn1.Searchable = True
OlvColumn2.Searchable = True
OlvColumn3.Searchable = True
OlvColumn4.Searchable = True
OlvColumn5.Searchable = True

I'm sure the PredicateBuilder solution will work, but ObjectListView comes with a simpler solution already.
TextMatchFilter can be limited to which columns it searches via the Columns property. Set this to an array of columns that you want to consider.
TextMatchFilter filter1 = TextMatchFilter.Contains(olvEmps, txtSearch.Text)
filter1.Columns = new [] { this.olvColumn1, this.olvColumn2 };
You can combine two filters using the CompositeAllFilter to match two or more other filters.
this.olvEmps.ModelFilter = new CompositeAllFilter(new List<IModelFilter> { filter1, filter2 });

Though I don't yet fully understand your deal, I'll give it a shot with the PredicateBuilder that is part of the LINQKit assembly which you can download here.
As such, filtering on multiple columns shall get easy. Perhaps shall you consider to reset the binding of your ObjectListView control once your source collection has been filtered.
Grossly, I would do about the following:
Load your datum;
Display them through data binding;
Once a column is clicked for filter, make a call to your "Filter" method which will apply your predicates;
Rebind your control with the new filtered collection.
Please refer to the PredicateBuilder documentation at the link provided previously. Another example to building dynamic filters is illustrated here: "How would this query translate into a dynamic Linq expression?" for a search engine I implemented.
In my case, the filters were applied directly against the database results. Aside, it can even be used in your situation with in-memory datum since it is Linq based.
I'm sure I'll be able to provide further assitance when you post your code sample for filtering the information.
EDIT #1
After I have read the code sample provided, here's what I believe would do the trick. As for the Searchable property, I am no familiar of this approach, so maybe I can miss something important out of your code and if it is so, feel free to point me what I could have missed. =)
Note that I assume that all of your datum are string, since I am verifying whether your datum is null or white space. Furthermore, the way I see it, to filter a result set is to bring visible only records which meet certain criterion. You don't want to see what doesn't meet the criterion. It's the same as a WHERE clause in SQL.
public class FilterCriterion {
public bool HasEmployeeName { get { return !string.IsNullOrWhiteSpace(EmployeeName); } }
public bool HasEmployeeNumber { get { return !string.IsNullOrWhiteSpace(EmployeeNumber); } }
public bool HasDepartment { get { return !string.IsNullOrWhiteSpace(Department); } }
public string EmployeeName { get; set; }
public string EmployeeNumber { get; set; }
public string Department { get; set; }
}
The FilterCriterion class shall be used to apply any filter that you want against your data source, collection or whatsoever.
var employees = LoadEmployeesFromUnderlyingDataStore();
var criterion = new FilterCriterion();
switch(searchMeth) {
case "Name": filter.EmployeeName = "the name to filter by"; break;
case "EmployeeNumber": filter.EmployeeNumber = "the number to filter by"; break;
case "Department": filter.Department = "the department to filter by"; break;
}
var filter = PredicateBuilder.True<Employee>(); // assuming you have an employee class.
if (criterion.HasEmployeeName)
filter.And(e => e.Name.ContainsLike(criterion.EmployeeName));
if (criterion.HasEmployeeNumber)
filter.And(e => e.EmployeeNumber.ContainsLike(criterion.EmployeeNumber));
if (criterion.HasDepartment)
filter.And(e => e.Department.ContainsLike(criterion.Department));
var filteredEmployees = employees.Where(filter);
// Supply your ObjectListView the way you're used to and this shall function.
Aside, you could also, if you have to deal with such string variables write a ContainsLike extension method to the string class.
namespace System {
public static class StringExtensions {
public static bool ContainsLike(this string input, string value) {
if (string.IsNullOrWhiteSpace(input) || string.IsNullOrWhiteSpace(value)) return false;
input = input.ToLower().RemoveDiacritics();
value = value.ToLower().RemoveDiacritics();
if (string.IsNullOrWhiteSpace(input) || string.IsNullOrWhiteSpace(value)) return false;
return input.Contains(value);
}
public static string RemoveDiacritics(this string input) {
return input == null ? null :
Encoding.ASCII.GetString(Encoding.GetEncoding(1251).GetBytes(input));
}
}
}
I do hope this helps, otherwise inform me of what I misunderstood from your question and we'll try to figure this out together.
Should you need the VB version of this code, I'll try to translate to the best of my VB knowledge.
This code is provided as is and has not been tested, except for both the string extension methods.