i have a Datatable in which there are Columns are
Assigned to
Storyid,
Completed,
Effort. assigned to person can have Same Storyid with diffrent or same (Completed,Effort hours)(image attached)
input datatable
i want dataTable to like in this form where Assigned to Effort and completed hours will be Sum and there storyid's(image attached below
output datatable
I hope this is what you are looking for
var result = yourDatatable
.GroupBy(e => e.AssignedTo)
.ToList()
.Select(eg => new
{
AssignedTo = eg.Key,
CompletedSum = eg.Sum(p=>p.completed),
EfforSum = eg.Sum(p=>p.effort),
StoryIds = string.Join(",", eg.Select(i => i.storyid))
});
I used .Net framwork 4.0 with WinForm application component DataGridView and set DataSource with DataTable.Then there's a button to add row into DataGridView.
That code like this.
gridTable = (DataTable)dgrMainGrid.DataSource;
DataRow dr = gridTable.NewRow();
Before adding New Row into DataTable I checked if there's a duplicate row.To do that I used this LINQ Query.
//Item Code cannot duplicate
var results = from itmCode in gridTable.AsEnumerable()
where (itmCode.Field<string>("Item Code") == txtGrdItmLoc.Text)
select itmCode;
There after how I check the duplicate rows available or not in the data table?
if(//doWhatever function here ){
//if there's duplicate row values
isNotDuplicate = false;
}
else{
isNotDuplicate=true;
}
Before go to following step I need to get is there a duplicate or not and set it into isNotDuplicate variable or similar thing to check that. so i think to count the results rows but there's no such function to count 'var results`, Any possibility to do that?
if (!isDuplicate)
{
dr["#"] = true;
dr["Item Code"] = lSysItemCode;
dr["Stock Code"] = txtGdrItmItemLoc.Text;
dr["Brand"] = txtGrdItmBrand.Text;
dr["Model No"] = cmbGrdItmModel.SelectedValue.ToString();
gridTable.Rows.Add(dr);
dgrMainGrid.DataSource = gridTable;
}
I can use for loop with DataTable and check whether it's contain new value that equals to "Item Code" but I looking alternative method with linq.
Simply I'm looking replacement for this by using linq.
foreach (DataRow r in gridTable.Rows) {
if (r["Item Code"].ToString() == txtGrdItmLoc.Text) {
isDuplicate = true;
}
}
Sample Project : http://1drv.ms/1K4JnHt
Sample Code : http://pastebin.com/v7NMdUrf
You have not made it clear that in your DataTable if you are looking for duplicates for any specific Item Code or for any Item Code. Anyways,here is the code for both the scenarios:-
If you are looking for duplicates for any specific Item Code then you can simply check the count like this:-
bool istxtGrdItmLocDuplicate = gridTable.AsEnumerable()
.Count(x => x.Field<string>("ItemCode") == txtGrdItmLoc.Text) > 1;
If you are looking for duplicates in the entire DataTable, then simply group by Item Code and check the respective count for each Item Code like this:-
bool isDuplicate = gridTable.AsEnumerable()
.GroupBy(x => x.Field<string>("ItemCode")
.Any(x => x.Count() > 1);
IEnumerable<T> has a Count() method (check here), if you are not seeing it in intellisense then you are missing some using instruction, like using System.Linq; or some other...
Then you would just do:
if(results.Count()>0){
//if there's duplicate row values
isNotDuplicate = false;
}
else
{
isNotDuplicate=true;
}
First cast it to IEnumerable :
Convert DataRowCollection to IEnumerable<T>
Then you can use LINQ extension methods to do something like this (to check all values that has duplicates):
var duplicates = resultsList.Where(r => resultsList.Count(r2 => r2.Field<string>("Item Code") == r.Field<string>("Item Code")) > 0);
If you want check each value for duplicate you can use .Count method, something like this:
bool hasDuplicates = resultsList.Count(r2 => r2.Field<string>("Item Code") == "your code") > 1;
Ok, if for some reason this doesn't work you can write this function yourself:
public static class Helper
{
// or other collection type
public static int MyCount<T>(this IEnumerable<T> collection, Func<T, bool> function)
{
int count = 0;
foreach (T i in collection)
if (function(i)) ++count;
return count;
}
}
And use it like :
results.MyCount(r => r.Field<string>("Item Code") == "Item Code");
Is there a way to get the list of FileNames in a DataTable without using a foreach loop?
DataTable dtOutput = new DataTable();
dtOutput.Columns.Add("FileName", typeof(string));
dtOutput.Columns.Add(Col2..., typeof(decimal));
...
foreach (string file in Directory.EnumerateFiles(txtBoxReadFrom.Text, txtBoxTargetFilter.Text))
{
dtOutput.Rows.Add(Path.GetFileName(file));
}
progressBar1.Maximum = dtOutput.Rows.Count;
Linq hides the loops from you, it uses them anyway:
List<String> allFileNames = dtOutput.AsEnumerable()
.Select(r => r.Field<string>("FileName"))
.ToList();
But why do you want a list at all when you already have the table which is also an in-memory collection?
If you want to diplays these file-names in another multiline TextBox you can use:
txtBoxWriteTo.Lines = dtOutput.AsEnumerable()
.Select(r => r.Field<string>("FileName"))
.ToArray();
Convert the DataTable object to Enumerable().
Apply the select clause with the column name as field name.
Cast it to a string array.
string[] strSummCities = dtTemp1.AsEnumerable().Select(s => s.Field<string>("City")).ToArray<string>();
Hope this will help t resolve your query.
you should add a reference to System.Data.DataSetExtension in order to have the CopyToDataTable() for enumerable values, after this you can use:
DataTable dtOutput =
Directory.EnumerateFiles(txtBoxReadFrom.Text, txtBoxTargetFilter.Text).Select(r =>
{
DataRow row = dtOutput.NewRow();
row["fileName"] = r;
return row;
}).CopyToDataTable();
How can the query below be modified to include a column for row number (ie: one-based index of results)?
var myResult = from currRow in someTable
where currRow.someCategory == someCategoryValue
orderby currRow.createdDate descending
select currRow;
EDIT1: I'm looking for the results to be {idx, col1, col2...col-n} not {idx, row}.
EDIT2: The row number should correspond to result rows not the table rows.
EDIT3: I DataBind these results to a GridView. My goal was to add a row number column to the GridView. Perhaps a different approach would be better.
Use the method-syntax where Enumerable.Select has an overload with the index:
var myResult = someTable.Select((r, i) => new { Row = r, Index = i })
.Where(x => x.Row.someCategory == someCategoryValue)
.OrderByDescending(x => x.Row.createdDate);
Note that this approach presumes that you want the original index of the row in the table and not in the filtered result since i select the index before i filter with Where.
EDIT: I'm looking for the results to be {idx, col1, col2...col-n} not
{idx, row}. The row number should correspond to result rows not
the table rows.
Then select the anonymous type with all columns you need:
var myResult = someTable.Where(r => r.someCategory == someCategoryValue)
.OrderByDescending(r => r.createdDate)
.Select((r, i) => new { idx = i, col1 = r.col1, col2 = r.col2, ...col-n = r.ColN });
Use this Select method:
Projects each element of a sequence into a new form by incorporating the element's index.
Example:
var myResult = someTable.Where(currRow => currRow.someCategory == someCategoryValue)
.OrderByDescending(currRow => currRow.createdDate)
.Select((currRow, index) => new {Row = currRow, Index = index + 1});
In response to your edit:
If you want a DataTable as result, you can go the non-Linq way by simply using a DataView and add a additional column afterwards.
someTable.DefaultView.RowFilter = String.Format("someCategory = '{0}'", someCategoryValue);
someTable.DefaultView.Sort = "createdDate";
var resultTable = someTable.DefaultView.ToTable();
resultTable.Columns.Add("Number", typeof(int));
int i = 0;
foreach (DataRow row in resultTable.Rows)
row["Number"] = ++i;
what about?
int i;
var myResult = from currRow in someTable
where currRow.someCategory == someCategoryValue
orderby currRow.createdDate descending
select new {Record = i++, currRow};
Just for fun, here's an alternative to Select with two arguments:
var resultsWithIndexes = myResult.Zip(Enumerable.Range(1, int.MaxValue - 1),
(o, i) => new { Index = i, Result = o });
According to you edit 1. NO, YOU CAN'T Linq returns the table as it is. You can build each column, but you lose the power of mapped entities.
This has been asked multiple times before: How do you add an index field to Linq results
There is no straightforward way if want to keep a flat list of columns (i.e. OP's Edit2) and also want a generic solution that works with any IEnumerable without requiring you to list out the set of expected columns.
However, there is a roundabout way to kinda go about it which is to dump the query results into a DataTable using the ToDataTable() method from here and then add a RowNumber column to that table.
var table = query.ToList().ToDataTable();
table.Columns.Add("RowNum", typeof(int));
int i = 0;
foreach (DataRow row in table.Rows)
row["RowNum"] = ++i;
This would likely cause performance issues with large datasets but it's not insanely slow either. On my machine a dataset with ~6500 rows took 33ms to process.
If your original query returned an anonymous type, then that type definition will get lost in the conversion so you'll lose the static typing on the column names of the resulting IEnumerable when you call table.AsEnumerable(). In other words, instead of being able to write something like table.AsEnumerable().First().RowNum you instead have to write table.AsEnumerable().First()["RowNum"]
However, if you don't care about performance and really want your static typing back, then you can use JSON.NET to convert the DataTable to a json string and then back to a list based on the anonymous type from the original query result. This method requires a placeholder RowNum field to be present in the original query results.
var query = (from currRow in someTable
where currRow.someCategory == someCategoryValue
orderby currRow.createdDate descending
select new { currRow.someCategory, currRow.createdDate, RowNum = -1 }).ToList();
var table = query.ToDataTable();
//Placeholder RowNum column has to already exist in query results
//So not adding a new column, but merely populating it
int i = 0;
foreach (DataRow row in table.Rows)
row["RowNum"] = ++i;
string json = JsonConvert.SerializeObject(table);
var staticallyTypedList = JsonConvert.DeserializeAnonymousType(json, query);
Console.WriteLine(staticallyTypedList.First().RowNum);
This added about 120ms to the processing time for my 6500 item dataset.
It's crazy, but it works.
I know I'm late to the party, but I wanted to show what worked for me.
I have a list of objects, and the object has an integer property on it for "row number"... or in this case, "Sequence Number". This is what I did to populate that field:
myListOfObjects = myListOfObjects.Select((o, i) => { o.SequenceNumber = i; return o; }).ToList();
I was surprised to see that this worked.
This one helped me in my case - Excel sheet extraction. anonymous type
var UploadItemList = ItemMaster.Worksheet().AsEnumerable().Select((x, index) => new
{
Code = x["Code"].Value == null ? "" : x["Code"].Value.ToString().Trim(),
Description = x["Description"].Value == null ? "" : x["Description"].Value.ToString().Trim(),
Unit = x["Unit"].Value == null ? "" : x["Unit"].Value.ToString().Trim(),
Quantity = x["Quantity"].Value == null ? "" : x["Quantity"].Value.ToString().Trim(),
Rate = x["Rate"].Value == null ? "" : x["Rate"].Value.ToString().Trim(),
Amount = x["Amount"].Value == null ? "" : x["Amount"].Value.ToString().Trim(),
RowNumber = index+1
}).ToList();
int Lc = 1;
var Lst = LstItemGrid.GroupBy(item => item.CategoryName)
.Select(group => new { CategoryName = group.Key, Items = group.ToList() ,RowIndex= Lc++ })
.ToList();
I am using LINQ query to filter data from a datatable and placing the data in to another datatable. For this I am using foreach statement to copy values from var to datatable. The datatable will be containing a very huge no. of rows so can you suggest me a way in which I can do the copying in a single go?
var drdatedisp = from row in dtfullreport.AsEnumerable()
group row by row.Field<string>("Order_Date") into g
select new
{
Order_Date = g.Key,
totalQnty = g.Sum(a => a.Field<int>("Item_Quantity")),
totalTax = g.Sum(a => float.Parse(a.Field<decimal>("TAXAMT").ToString())),
totalAmt = g.Sum(a => float.Parse(a.Field<decimal>("VALAMT").ToString()))
};
DataTable dtdatedisp = new DataTable();
dtdatedisp.Columns.Add("Order_Date");
dtdatedisp.Columns.Add("Item_Quantity");
dtdatedisp.Columns.Add("TAXAMT");
dtdatedisp.Columns.Add("VALAMT");
dtdatedisp.Rows.Clear();
foreach (var g in drdatedisp)
{
DataRow newRow1 = dtdatedisp.NewRow();
newRow1[0] = g.Order_Date;
newRow1[1] = g.totalQnty;
newRow1[2] = String.Format("{0:0.00}", g.totalTax);
newRow1[3] = String.Format("{0:0.00}", g.totalAmt);
dtdatedisp.Rows.Add(newRow1);
}
}
please see that there will be very less no of iterations....
is there any way ?? Can you Help me ??
There is a extension method called CopyToDataTable which is unfortunately on IEnumerable Data Row object. But with the use of following link, you can create/copy same extension method which will be called on any IEnumerable object And this would match your requirement.
Here is the link
With this you can directly write something like this in your code
drdatedisp.CopyToDataTable();
use CopyToDataTable(); Verified the result:
var results = (from myRow in myData.AsEnumerable()
where myRow.Field<double>("Num1") == 1
select myRow).CopyToDataTable();
DataTable dtTemp = (DataTable)results;
gvMain.DataSource = dtTemp;