Develop Reference

How to join 2 data tables

DataTable1
LoginId LoginName SCount
1 Mohit 20
3 Riya 25
DataTable2
LoginId LoginName ECount
2 Smita 11
3 Riya 13
I want to show result like this
LoginName Scount Ecount Total
Mohit 20 0 20
Smita 0 11 11
Riya 25 13 38
Query:
DataTable dtResult = new DataTable();
DataTable UserCount1 = new DataTable();
DataTable UserCount2 = new DataTable();
// Assigning value to datatable
if (ds != null)
{
UserCount1 = ds.Tables["UserCount1"];
UserCount2 = ds.Tables["UserCount2"];
}
var LinqResult =
from dataRows1 in UserCount1.AsEnumerable()
join dataRows2 in UserCount2.AsEnumerable()
on dataRows1.Field<string>("LoginId") equals dataRows2.Field<string>("LoginId") into lj
from r in lj.DefaultIfEmpty()
select dtResult.LoadDataRow(new object[]
{
dataRows2.Field<string>("LoginName"),
r == null ? 0 : r.Field<int>("SCount"),
r == null ? 0 : r.Field<int>("ECount")
}, false);
Getting complie time error in
select statement( dataRows2.Field<string>("LoginName"),)
that dataRows2 does not exist in current context.
How to achieve that result?

For the easy and strongly typed solution, I would strongly suggest defining classes, such as:
class User1 { public int LoginId; public string LoginName; public int SCount; }
class User2 { public int LoginId; public string LoginName; public int ECount; }
to enable LINQ extension methods, then your task becomes quite easy (explanation in comments in code):
// Sample data.
DataTable UserCount1 = new DataTable();
DataTable UserCount2 = new DataTable();
UserCount1.Columns.AddRange(new DataColumn[] { new DataColumn("LoginId"), new DataColumn("LoginName"), new DataColumn("SCount") });
UserCount2.Columns.AddRange(new DataColumn[] { new DataColumn("LoginId"), new DataColumn("LoginName"), new DataColumn("ECount") });
UserCount1.Rows.Add(1, "Mohit", 20);
UserCount1.Rows.Add(3, "Riya", 25);
UserCount2.Rows.Add(2, "Smita", 31);
UserCount2.Rows.Add(3, "Riya", 13);
// Here we create lists of our users.
List<User1> users1 = new List<User1>();
List<User2> users2 = new List<User2>();
foreach (DataRow row in UserCount1.Rows)
users1.Add(new User1() { LoginId = int.Parse(row["LoginId"].ToString()), LoginName = (string)row["LoginName"], SCount = int.Parse(row["SCount"].ToString()) });
foreach (DataRow row in UserCount2.Rows)
users2.Add(new User2() { LoginId = int.Parse(row["LoginId"].ToString()), LoginName = (string)row["LoginName"], ECount = int.Parse(row["ECount"].ToString()) });
// Full outer join: first we join, then add entries, that were not included.
var result = users1.Join(users2, u1 => u1.LoginId, u2 => u2.LoginId, (u1, u2) => new { LoginId = u1.LoginId, LoginName = u1.LoginName, SCount = u1.SCount, ECount = u2.ECount, Total = u1.SCount + u2.ECount }).ToList();
result.AddRange(users1.Where(u1 => !result.Select(u => u.LoginId).Contains(u1.LoginId)).Select(u1 => new { LoginId = u1.LoginId, LoginName = u1.LoginName, SCount = u1.SCount, ECount = 0, Total = u1.SCount }));
result.AddRange(users2.Where(u2 => !result.Select(u => u.LoginId).Contains(u2.LoginId)).Select(u2 => new { LoginId = u2.LoginId, LoginName = u2.LoginName, SCount = 0, ECount = u2.ECount, Total = u2.ECount }));
Then you can construct another result DataTable, for which I don't see any reason.

How can use dynamic columns in linq?

how can i use dynamic columns instead of this query
id = row.Field<int>("id") ,
rec_date = row.Field<string>("rec_date")
var result = from row in dt.AsEnumerable()
group row by new
{
id = row.Field<int>("id") ,
rec_date = row.Field<string>("rec_date")
} into section1
select new
{
section1.Key.id,
section1.Key.rec_date,
children = from l2 in section1
select new
{
tax_rate = l2.Field<string>("tax_rate"),
tax_amount = l2.Field<string>("tax_amount")
}
};
var jsonString = JsonConvert.SerializeObject(result);

How to join two lists and fill a datagridview

I have two list (1st with values from a website, 2nd with values from a .csv file) and I'd like to join them in another list, starting two equals values, and display it in a datagridview.
Before to post the code, I'd like to say that I tried to fill my datagridview with these two lists separately and they work.
I didn't get any error, but I can't see my datagridview with values.
I'm going to post my code and explain it.
First List Code:
var url = textBox5.Text;
//var url = "http://www.betexplorer.com/soccer/norway/tippeligaen/results/";
var web = new HtmlWeb();
var doc = web.Load(url);
Bets = new List<Bet>();
// Lettura delle righe
var Rows = doc.DocumentNode.SelectNodes("//tr");
foreach (var row in Rows)
{
if (!row.GetAttributeValue("class", "").Contains("rtitle"))
{
if (string.IsNullOrEmpty(row.InnerText))
continue;
var rowBet = new Bet();
foreach (var node in row.ChildNodes)
{
var data_odd = node.GetAttributeValue("data-odd", "");
if (string.IsNullOrEmpty(data_odd))
{
if (node.GetAttributeValue("class", "").Contains("first-cell"))
{
rowBet.Match = node.InnerText.Trim();
var matchTeam = rowBet.Match.Split(new[] { " - " }, StringSplitOptions.RemoveEmptyEntries);
rowBet.Home = matchTeam[0];
rowBet.Host = matchTeam[1];
}
if (node.GetAttributeValue("class", "").Contains("result"))
{
rowBet.Result = node.InnerText.Trim();
var matchPoints = rowBet.Result.Split(new[] { ':' }, StringSplitOptions.RemoveEmptyEntries);
int help;
if (int.TryParse(matchPoints[0], out help))
{
rowBet.HomePoints = help;
}
if (matchPoints.Length == 2 && int.TryParse(matchPoints[1], out help))
{
rowBet.HostPoints = help;
}
}
if (node.GetAttributeValue("class", "").Contains("last-cell"))
rowBet.Date = node.InnerText.Trim();
}
else
{
rowBet.Odds.Add(data_odd);
}
}
if (!string.IsNullOrEmpty(rowBet.Match))
Bets.Add(rowBet);
}
}
Second List & Combined List Code:
string FileName = #"C:\mydir\testcsv.csv";
OleDbConnection conn = new OleDbConnection
("Provider=Microsoft.Jet.OleDb.4.0; Data Source = " +
Path.GetDirectoryName(FileName) +
"; Extended Properties = \"Text;HDR=YES;FMT=Delimited\"");
conn.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter
("SELECT * FROM " + Path.GetFileName(FileName), conn);
DataSet ds = new DataSet("Temp");
adapter.Fill(ds);
conn.Close();
// DataTable dt = new DataTable();
DataTable dt = ds.Tables[0];
//dataGridView2.DataSource = dt;
// dataGridView2.DataMember = "Table";
List<HT> matchlist = new List<HT>();
matchlist = (from DataRow dr in dt.Rows
select new HT()
{
Home = dr["Home"].ToString().Replace("Milan", "AC Milan").Replace("Roma", "AS Roma"),
Host = dr["Host"].ToString().Replace("Milan", "AC Milan").Replace("Roma", "AS Roma"),
ScoreHome = dr["ScoreHome"].ToString(),
ScoreAway = dr["ScoreAway"].ToString(),
//Segno = dr["Segno"].ToString(),
//odd1 = dr["odd1"].ToString(),
//oddx = dr["oddx"].ToString(),
//odd2 = dr["odd2"].ToString()
}).ToList();
// dataGridView2.DataSource = matchlist;
var combinedDataList = (from d1 in Bets
//join d2 in dataList2 on d1.Home equals d2.Home
join d2 in matchlist on new { d1.Home, d1.Host } equals new { d2.Home, d2.Host }
select new CombinedData
{
Data = d1.Date,
Home = d1.Home,
Away = d1.Host,
HSFT = d1.HomePoints,
ASFT = d1.HostPoints,
HSHT = d2.ScoreHome,
ASHT = d2.ScoreAway,
HODD = d1.odd1,
XODD = d1.oddX,
AODD = d1.odd2,
RisFin = d1.RisFin,
Over05SH = d1.over05sh,
Over05FT = d1.Over05FT,
Over15FT = d1.Over15FT,
Over25FT = d1.Over25FT,
Over35FT = d1.Over35FT,
Over45FT = d1.Over45FT
}).OrderBy(p => p.HODD);
dataGridView2.DataSource = combinedDataList;
Thank you for your attention. Have a fantastic sunday!
EDIT: I delete unnecessary code
EDIT2: I add the screen of my single list output. Let's see:
First List:
Second List:
So, I'd like to merge "ScoreHome" and "ScoreAway" from the second list in my first list based on "Home" and "Host" that I have in both lists.

Index was outside the bounds of the array when adding class to list C#

Exception: Index was outside the bounds of the array.
First off, I'm familiar with this exception and I have fixed it before but I'm getting this exception at a very strange line in my code. It is being thrown when I'm adding a user created class to a list of classes in my code. I'm completely lost as to why it is throwing this exception and how to fix it.
public static async Task getData()
{
// initialize everything
List<StockData> stockData = new List<StockData>();
List<StockMarketCompare> stockCompareData = new List<StockMarketCompare>();
List<StockData> sandpInfo = new List<StockData>();
List<StockData> sandpDateInfo = new List<StockData>();
List<StockData> amexList = new List<StockData>();
List<DateTime> completedDates = new List<DateTime>();
SymbolInfo symbolClass = new SymbolInfo();
List<SymbolInfo> ratingSymbols = new List<SymbolInfo>();
List<StockRating> ratingList = new List<StockRating>();
bool isGoodToGo = false;
string symbol, market;
int activeSymbolsCount = 0;
int rowCount = 0, completedRowCount = 0;
DateTime date = new DateTime();
DateTime searchDate = new DateTime();
using (SqlConnection connection = new SqlConnection("connectionstring"))
using (SqlCommand sandpCommand = new SqlCommand("select * from dbo.DailyGlobalData where Symbol='" + Calculations.sp500 + "'", connection))
using (SqlDataAdapter sandpAdapter = new SqlDataAdapter(sandpCommand))
using (DataTable sandpTable = new DataTable("sandp"))
using (SqlCommand stockRatingsCommand = new SqlCommand("select * from dbo.StockRatings", connection))
using (SqlDataAdapter stockRatingsAdapter = new SqlDataAdapter(stockRatingsCommand))
using (DataTable stockRatingsTable = new DataTable("stockratings"))
{
try
{
// fill the sandptable
sandpAdapter.Fill(sandpTable);
if (sandpTable != null)
{
var sandpQuery = from c in sandpTable.AsEnumerable()
select new StockData { Close = c.Field<decimal>("Close"), Date = c.Field<DateTime>("Date"), High = c.Field<decimal>("High"), Low = c.Field<decimal>("Low"), Volume = c.Field<Int64>("Volume") };
sandpInfo = sandpQuery.AsParallel().ToList();
}
// fill the stockratingstable
stockRatingsAdapter.Fill(stockRatingsTable);
if (stockRatingsTable != null)
{
activeSymbolsCount = stockRatingsTable.Rows.Count;
var symbolsAmountQuery = from c in stockRatingsTable.AsEnumerable()
select new SymbolInfo { Symbol = c.Field<string>("Symbol"), Market = c.Field<string>("Market") };
ratingSymbols = symbolsAmountQuery.AsParallel().ToList();
}
for (int i = 0; i < activeSymbolsCount; i++)
{
symbol = ratingSymbols.AsParallel().ElementAtOrDefault(i).Symbol;
market = ratingSymbols.AsParallel().ElementAtOrDefault(i).Market;
ratingList = new List<StockRating>();
using (SqlCommand historicalRatingsCommand = new SqlCommand("select * from dbo.OldStockRatings where Symbol='" + symbol + "' and Market='" + market + "'", connection))
using (SqlDataAdapter historicalRatingsAdapter = new SqlDataAdapter(historicalRatingsCommand))
using (DataTable historicalRatingsTable = new DataTable("historicalratings"))
{
// fill the historical ratings table
historicalRatingsAdapter.Fill(historicalRatingsTable);
if (historicalRatingsTable != null)
{
completedRowCount = historicalRatingsTable.AsEnumerable().AsParallel().Count();
completedDates = historicalRatingsTable.AsEnumerable().AsParallel().Select(d => d.Field<DateTime>("Date")).ToList();
}
}
using (SqlCommand amexCommand = new SqlCommand("select * from dbo.DailyAmexData where Symbol='" + symbol + "'", connection))
using (SqlDataAdapter amexAdapter = new SqlDataAdapter(amexCommand))
using (DataTable amexTable = new DataTable("amexdata"))
{
// fill the amex data table
amexAdapter.Fill(amexTable);
if (amexTable != null)
{
var amexFillQuery = from c in amexTable.AsEnumerable()
select new StockData { Close = c.Field<decimal>("Close"), Date = c.Field<DateTime>("Date"), High = c.Field<decimal>("High"), Low = c.Field<decimal>("Low"), Volume = c.Field<Int64>("Volume") };
amexList = amexFillQuery.AsParallel().ToList();
rowCount = amexList.AsParallel().Count();
}
}
Parallel.For(0, rowCount - 30, new ParallelOptions
{
MaxDegreeOfParallelism = Environment.ProcessorCount
}, async j =>
{
if (amexList.AsParallel().Count() > 0)
{
date = amexList.AsParallel().ElementAtOrDefault(j).Date;
searchDate = date.Subtract(TimeSpan.FromDays(60));
if (completedDates.Contains(date) == false)
{
var amexQuery = from c in sandpInfo
where c.Date >= searchDate && c.Date <= date
join d in amexList on c.Date equals d.Date
select new StockMarketCompare { stockClose = d.Close, marketClose = c.Close };
var amexStockDataQuery = from c in amexList
where c.Date >= searchDate && c.Date <= date
select new StockData { Close = c.Close, High = c.High, Low = c.Low, Volume = c.Volume, Date = c.Date };
stockCompareData = amexQuery.AsParallel().ToList();
stockData = amexStockDataQuery.AsParallel().ToList();
isGoodToGo = true;
}
else
{
isGoodToGo = false;
}
}
if (completedDates.Contains(date) == false)
{
var sandpDateQuery = from c in sandpInfo
where c.Date >= searchDate && c.Date <= date
select c;
sandpDateInfo = sandpDateQuery.AsParallel().ToList();
symbolClass = new SymbolInfo() { Symbol = symbol, Market = market };
isGoodToGo = true;
}
else
{
isGoodToGo = false;
}
if (isGoodToGo)
{
StockRating rating = performCalculations(symbolClass, date, sandpInfo, stockData, stockCompareData);
if (rating != null)
{
**ratingList.Add(rating);** // getting the exception thrown here
}
}
});
// now save the results to the table outside the parallel for loop
ratingList.RemoveAll(item => item == null);
List<StockRating> masterList = ratingList.DistinctBy(j => j.date).ToList();
saveToTable(masterList, symbol, market);
// close the connection
connection.Close();
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
// close the connection
connection.Close();
}
}
}

List<T> is not thread safe and you are calling .Add from inside your Parallel.For. You either need to lock on the Add or use a threadsafe collection in the System.Collections.Concurrent namespace.
This is not your only threading error you have, for example also inside your Parallel.For you assign several variables that are all declared in the scope outside of the loop. Your various threads are going to be writing over each other assigning those values.

ratingsList is not thread safe because List<T> is not guaranteed to be thread safe (except for static methods), yet you are modifying it from multiple threads.
Public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
It is safe to perform multiple read operations on a List, but issues can occur if the collection is modified while it’s being read. To ensure thread safety, lock the collection during a read or write operation. To enable a collection to be accessed by multiple threads for reading and writing, you must implement your own synchronization. For collections with built-in synchronization, see the classes in the System.Collections.Concurrent namespace. For an inherently thread–safe alternative, see the ImmutableList class.
https://msdn.microsoft.com/en-us/library/6sh2ey19%28v=vs.110%29.aspx
Use a thread safe collection instead.

How merge two sequences into one?

I have some working code that retrieves data from data base. It is interesting for me to get some better code for my solution. Are there some ways to combine two queries into one or something like this?
Dim customerTitlesAndIDs = contex.CustomerTable.Select(Function(row) New
With {.ID = row.ID, .CustomerTitle = row.Title}).ToList()
Dim cutomerIdPayment = contex.CustomerPayments.Select(Function(table) New
With
{
.ID = table.CustomerID,
.Range = table.PaymentsRange,
.Values = table.Values
}).ToList()
Dim customerInfos As New List(Of SCustomerInfo)
For Each customer In customerTitlesAndIDs
Dim cID As Integer = customer.ID
customerInfo.Add(New SCustomerInfo(CreateCustomerTable(), cID, customer.CustomerTitle))
For Each cutomerPayments In cutomerIdPayment
If cutomerPayments.ID = cID Then
Dim rangeValue(1) As Object
rangeValue(0) = cutomerPayments.Range
rangeValue(1) = cutomerPayments.Values
Dim dtRow As DataRow = customerInfos.Last().PaymentTable.NewRow()
dtRow.ItemArray = rangeValue
customerInfos.Last().PaymentTable.Rows.Add(dtRow)
End If
Next
Next
Return customerInfos
Same code with C# (hope no syntax errors occurred):
var customerTitlesAndIDs = contex.CustomerTable.Select(row => new
{ .ID = row.ID, .CustomerTitle = row.Title }).ToList();
var cutomerIdPayment = contex.CustomerPayments.Select(table => new
{
.ID = table.CustomerID,
.Range = table.PaymentsRange,
.Values = table.Values
}).ToList();
List<SCustomerInfo> customerInfos = new List<SCustomerInfo>;
foreach (var customer in customerTitlesAndIDs)
{
int cID = customer.ID;
customerInfos.Add(new SCustomerInfo(CreateCustomerTable(), cID, customer.CustomerTitle));
foreach (var cutomerPayments in cutomerIdPayment)
{
if (cutomerPayments.ID = cID)
{
object[] rangeValue = new object[1] {cutomerPayments.Range, cutomerPayments.Values};
DataRow dtRow = customerInfos.Last().PaymentTable.NewRow();
dtRow.ItemArray = rangeValue;
customerInfos.Last().PaymentTable.Rows.Add(dtRow);
}
}
}
SCustomerInfo represented by folowing Structure (code is simplified):
Public Structure SWindAltitude
Public PaymentTableAs DataTable
Public Title As String
Public ID As Integer
End Structure
Both C# and VB.NET solutions will be helpful.

Try something like this, utilizing navigation properties (you'll probably have to massage it as I don't know the exact makeup of your data structures):
var customerQuery = context.CustomerTable.Select( ct =>
new {
ct.ID,
ct.CustomerTitle,
// use nav property to get customer payments
CustomerPayments = ct.CustomerPayments.Select( cp =>
new {
Range = cp.Range,
Values = cp.Values } ) } );
return customerQuery.ToArray()
.Select( cq =>
{
var retVal = new SCustomerInfo( CreateCustomerTable(), cq.ID, cq.CustomerTitle );
foreach( var customerPayment in cq.CustomerPayments )
{
var dtRow = cq.PaymentTable.NewRow();
dtRow.ItemArray = new object[] { customerPayment.Range, customerPayment.Values };
retVal.PaymentTable.Rows.Add( dtRow );
}
return retVal;
} );

if i understand right in c# with linq it will be something like this
var customerInfos = customerTitlesAndIDs.Select((c)=>{
var ci = new SCustomerInfo(CreateCustomerTable(), c.ID, customer.CustomerTitle);
ci.PaymentTable = ci.PaymentTable.AsEnumerable().Union(
cutomerIdPayment.Where(j=>j.ID == c.ID)
.Select(j=>{
var dtRow = ci.PaymentTable.NewRow();
dtRow.ItemArray = new object[] {
customerPayment.Range,
customerPayment.Values
};
return dtRow;
})).CopyToDataTable();
return ci;
}).ToList();

I think you can use the Linq provided function Sequence.concat() as described here: http://msdn.microsoft.com/en-us/library/vstudio/bb386979(v=vs.100).aspx