LINQ To SQL Using GROUP BY And COUNT(DISTINCT)
Jan 15, 2009I have to perform the following SQL query: select answer_nbr, count(distinct user_nbr)
from tpoll_answer where poll_nbr = 16 group by answer_nbr The LINQ to SQL query
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How To Group Distinct Columns In A Linq Query
Nov 4, 2010The following data is created by joining two sql tables together:I would like to group together distinct rows of DateStamp/UserName/ StudentName/ InstructorName/TableName/PrimaryKey (I'll call this 'group records') and then group under these ColumnName/PreviousValue/NewValue (I'll call this 'subgroup records')The end result would be that I could iterate through the 'group records' - there would be 5. In each 'group record', I could then iterate through the 'subgroup records'. The 5 groups would contain 3, 2, 5, 2 and 1 subgroup records respectively.What would be the syntax to create a query to do this? Ideally this would be in a vb.net linq syntax.
View 1 RepliesLinq Distinct Count Multiple Fields
Mar 24, 2012I have a Table:
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I'm trying by LINQ-query (VB.NET) to return a count for distinct value of Objects, Stuffs and Colours for every Room:
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Linq Group Count Items?
Dec 5, 2011I have this linq to entity
From r In ReceiptRepository.Fetch
Where
r.RECEIPTDATE >= ReportStartDate And
[Code]....
This is working fine, except the count property, it is just giving the number of group count. I don't know how to find out each Tender Count
Sql - Group By Having And Count As LINQ Query With Multiply Nested Tables?
Feb 28, 2012I have the following SQL query to return all Customers who have no OrderLines with no Parts assigned - i.e. I only want the customers within which every order line of every order has no parts assigned - (in the actual problem I am dealing with a different domain but have translated to customers/orders to illustrate the problem)
SELECT c.Customer_PK
FROM Customers c
INNER JOIN Orders o[code].....
This works but generates less than optimal SQL - it is doing a subquery for Count on each row of the customers query rather than using Group By and Having. I tried making the LINQ Group By syntax work but it kept putting the filter as a WHERE not a HAVING clause.Edit in response to Answers below: I am accepting JamieSee's answer as it addresses the stated problem, even though it does not produce the GROUP BY HAVING query I originally had.I am a VB developer so I have had a crack translating your code to VB, this is the closest I got to but it does not quite produce the desired output:
Dim qry = From c In context.Customers
Group Join o In context.Orders On c.Customer_PK Equals o.Customer_FK
Into joinedOrders = Group[cod].....
The problem I had is that I have to push "jl" into the Group By "Key" so I can reference it from the Where clause, otherwise the compiler cannot see that variable or any of the other variables appearing before the Group By clause.With the filter as specified I get all customers where at least one order has lines with no parts rather than only customers with no parts in any order.
C# - Get Distinct Rows From Datatable Using Linq (distinct With Mulitiple Columns)
Jul 13, 2010I am trying to distinct on multiple columns and get datarows from datatable. but getting error.
Dim query As IEnumerable(Of DataRow) =
(From row As DataRow In SourceTable.AsEnumerable() _
Select row.Field(Of String)("ColumnName1"),
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I want another datatable with distinct row based on given columns from SourceTable.
How To Count Distinct Value From DataGridView
May 31, 2010I need to Count row with Distinct from Datagridview.
View 2 RepliesGet Row Count Of Distinct Values In A DataTable Column?
Mar 13, 2012I have a DataTable that has several hundred rows.I want to get a row count of distinct values in a particular column.For example, I have a DataTable of Product Orders, but I want to get the number of unique Customers.
I was using this code, but I can't rely on it because my binding source is filtered from time to time.If my binding source has filtered out all rows datatable.DefaultView returns 0 rows.
Getting Count Of Non-distinct Items In List(of String)?
Feb 7, 2012On to my question.I have a List(of String) that contains multiple items in each index.
A list declared as:
Dim NewStrings As New List(Of String)
May contain the following:
item (0) - (1 MKNO ABC 2.45 STND 3.3)
item (1) - (1 MKGO ABC 1.34 STND 2.5)
item (2) - (1 MKNO ABC 2.45 STND 3.3)
item (3) - (1 MKNO ABC 2.45 STND 3.3)
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Distinct When Using Union On LINQ?
Nov 18, 2010When the user has typed in some information I would like to output possible matches in a descending order, so if someone types in a full first name and a full surname, it should be listed above a result where just the surname matches.I've done something similar in SQL before which worked perfectly, but this time I'd like to do it in LINQ.
Firstname, Surname, City, Country as string variables.
Dim DataEnum As IEnumerable(Of frmTelephone.clsPerson) = alPerson.OfType(Of frmTelephone.clsPerson)()
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.net - Linq To Object - Select Distinct
Mar 18, 2010I can't quite figure out why this Linq Statement isn't working as i would expect:
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I would assume that this would create a new collection of anonymous types, that would be distinct. Instead it creates a collection the size of the "ThisParentCollection" with duplicate "MyAnonymousType" in it (duplicate id's).
.net - LINQ To XML And Distinct Custom Class?
Oct 14, 2009I have a very interesting LINQ question. I have a document, that I am trying to filter results on, but to filter, I am matching on a REGEX result from one element of the XML. I have the following, working LINQ to XML to get the individual data that I'm looking for.
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Get Distinct Values From List(Of T) Using Linq?
Mar 10, 2012I have a List(Of Hardware) - the List is called HWModels
Class Hardware has the following Properties:
ModelName
Status
CPUStatus
MemoryStatus
DiskStatus
The List is populated by reading a CSV file, once it's populated, I want to return the distinct records based on the ModelName
I've attempted by doing it as follows:
(From a In HWModels Select a.ModelName).Distinct
But this isn't right because I end up with a list of only the ModelName's and nothing else.
How do I get the Distinct function to return all of the other class members within the list?
LINQ / Select Distinct From Dataset?
Aug 20, 2010I have a single columned datatable inside a single tabled dataset.I just want to convert this dataset to distinct rows. Here is my code, it gives compile error '.' expected.
Dim query = _
From email In ds.Tables(0) _
Select email.Field<string>("Email").Distinct()
EDIT: I changed to (Of String) and it works... BUT NOW 'query' is an ienumerable collection of characters... not a datatable... so how do I convert back easily without manually doing a loop?
Linq Join On Parameterized Distinct Key?
Sep 9, 2010I'm trying to LINQ two tables based on a dynamic key. User can change key via a combo box. Key may be money, string, double, int, etc. Currently I'm getting the data just fine, but without filtering out the doubles. I can filter the double in VB, but it's slooooow. I'd like to do it in the LINQ query right out of the gate.
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"Range variable name can be inferred only from a simple or qualified name with no arguments."
Linq Join On Parametrized Distinct Key?
Jun 9, 2011I'm trying to LINQ two tables based on a dynamic key. User can change key via a combo box. Key may be money, string, double, int, etc. Currently I'm getting the data just fine, but without filtering out the doubles. I can filter the double in VB, but it's slooooow. I'd like to do it in the LINQ query right out of the gate.
LinqMasterTable:
-------------------------------------------------------------
| AppleIndex | AppleCost | AppleColor | AppleDescription |
------------------------------------------------------------
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Select Distinct In Linq Query?
Jan 4, 2012I've a collection with the data like this.[code]...
how can select the distinct data using linq?
Use Linq For Select Distinct Values?
Mar 28, 2012I'm pretty new in Linq and the first problem I've is to select the Distinct values from a ObservableCollection( Of T)
I've tried with[code]...
Distinct Values In LINQ With Anonymous Types
Jul 2, 2011Supposing the referenced List below contains 2 elements:
Dim Countries = From c In List _
Select New With { .Country = c.Country, .CountryID = c.CountryID }
The code above returns
.Country=Spain .CountryID = 1
.Country=Spain .CountryID = 1
How can I get the distinct values? The Countries query should contain only
.Country=Spain .CountryID = 1
Linq To DataTable Not Producing Distinct Values?
Oct 19, 2010I have a datatable which has been dynamically generated from FoxPro tables using a UNION Select statement. e.g.SELECT * FROM x UNION SELECT * FROM y UNION SELECT * FROM Z ORDER By v_alue1This produces a datatable with about 100 rows, each containing many fields, one of which is c_olor. From this datatable, I would like to select the distinct colors and then output in a dropdown.I have a public class Color which just has one property which I can then use as the DataTextField and DataValueField for the dropdownlist
Public Class Color
Private _c_olor As String
Public Property c_olor() As String
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LINQ To SQL Grouping Multiple Columns With A Distinct Row
Aug 9, 2010I have the following table structure. I want to select distinct CustomerId and CustomerName, TotalCost.[code]
View 2 RepliesLINQ To SQL Select Distinct From Multiple Colums?
Apr 2, 2010I'm using LINQ to SQL to select some columns from one table. I want to get rid of the duplicate result also.
Dim customer = (From cus In db.Customers Select cus.CustomerId, cus.CustomerName).Distinct
Result:
1 David
2 James
1 David
3 Smith
2 James
5 Joe
Wanted result:
1 David
2 James
3 Smith
5 Joe
Can anyone show me how to get the wanted result?
Select Distinct Rows From Datatable In Linq
Jul 14, 2010I am trying to get distinct rows based on multiple columns (attribute1_name, attribute2_name) and get datarows from datatable using Linq-to-Dataset.[code]How to do thin Linq-to-dataset?
View 3 RepliesSelecting Distinct Within LINQ Of Data Rows
Oct 24, 2011I have a DataTable with about 64 columns, including "UserAnswer", "CorrectAnswer", and "QID_Lookup". I am building a LINQ that will select all the rows that have a correct answer (user answer matches correct answer), but I only want to select rows that have distinct "QID_Lookup".
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The problem is that the result set includes duplicate QID_Lookup values. How can I include only distinct QID_Lookup values? keep in mind that there are 64 columns, so if I can avoid it, I wouldn't want to list each column individually for selection.
C# - LINQ Select Distinct While Evaluating Multiple Rows
Jul 11, 2011I have an EnumerableRowCollection that looks like the following:
VendorCode | GroupType | Variance
01165 G .16
01165 G .16
01165 CH .16
01165 CH .18
07754 G .25
07754 G .25
07754 G .39
Essentially, this is a massive list of vendor codes, their groups, and price variances. I need to compose a query that will create a distinct list vendor codes and group types. The catch, however, is that I need to evaluate all of the variances associated with that particular VendorCode/GroupType to see if they are all the same - it they are not, I need to return some way of signifying that the group has a "custom" variance, otherwise it needs to return the value (ie: if they are all .16, then return .16, if there are multiple values, return "custom")
The result would look like this, based off of the list I showed above.
VendorCode | GroupType | Variance
01165 G .16
01165 CH custom
07754 G custom
I have no trouble getting a distinct list of VendorCode/GroupType - this is what I have so far:
Dim distinctList = From q In query Select q.VendorCode, q.GroupType, (evaluated q.Variance here?) Distinct
(where "query" is an EnumerableRowCollection(Of (anonymous type)))
I'm at a loss, though, on how to evaluate the variance property to get the result that I need?
C# - LINQ Select From IEnumerable With Distinct/GroupBy And Sorting?
Oct 19, 2010My particular example is fairly complex but I think the concept would apply equally to something like a logging system so I'll use that instead for ease of explanation. It's a ficticious example, please don't harp on or agonise over what is achitectually, programatically or morally wrong with the example itself
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I don't want to 'cheat' and resort to a long-winded way of doing it when performance isn't critical here and I'm moderately confident it can be done in a single LINQ statement.
GetHashCode When Implementing IEquatable Then Using The .Distinct Method In LINQ
Aug 18, 2011If I simply have this:>>
CODE:
Linq Join On Parameterized Distinct Key CASE INSENSITIVE?
Oct 7, 2010To revisit a previous question with a further stipulation..Anyone know how to do the following, IGNORING CASE?
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Linq To Datarow, Select Multiple Columns As Distinct?
Apr 16, 2010basically i'm trying to reproduce the following mssql query as LINQ
SELECT DISTINCT [TABLENAME], [COLUMNNAME] FROM [DATATABLE]
the closest i've got is
Dim query = (From row As DataRow In ds.Tables("DATATABLE").Rows _
Select row("COLUMNNAME") ,row("TABLENAME").Distinct
when i do the above i get the error
Range variable name can be inferred only from a simple or qualified name with no arguments.
i was sort of expecting it to return a collection that i could then iterate through and perform actions for each entry. maybe a datarow collection?
As a complete LINQ newb, i'm not sure what i'm missing.
i've tried variations on
Select new with { row("COLUMNNAME") ,row("TABLENAME")}
and get:
Anonymous type member name can be inferred only from a simple or qualified name with no arguments.
to get around this i've tried
Dim query = From r In ds.Tables("DATATABLE").AsEnumerable _
Select New String(1) {r("TABLENAME"), r("COLUMNNAME")} Distinct
however it doesn't seem to be doing the distinct thing properly.
C# - How To Get Count Of Each Group In MS Reports
Jan 16, 2012In MS Reports, I have a tablix(table) where I group on foo. How do I get the count for each group? This is how I would do it for the total count: =Count(Fields!foo.Value) , but it's not enough.
View 1 Replies