gefundeneID = drTerminal.AsEnumerable().Single(Function(s) s("TerminalID") = RandomID)Have an array of DataRow and want to look if the RandomID is in one of the rows.What's wrong with this code?
View 2 RepliesDim orders = From tt In testTable _
Order By tt.Item("OrderNumber") _
Select tt.Item("OrderNumber"), tt.Item("OrderId")
This is breaking. Is there a way to do this? I would have thought it was easy enough. Obviously, I thought wrong....
my code is
Dim rows() As Data.DataRow
rows = DataSet1.Tables(0).Select("unitname='Ltr'")
dim i as integer
for i = 0 to rows.count -1
MsgBox(rows(i).item(0)) '' HERE ERROR ITEM PROPERTY NOT FOUND
next
so i want a specific item in rows like this code we use in dataset...DSet.Tables(0).Rows(1).Item(1)
I have a datatable where there are 3 columns
ID | Name | Date
and i have 4 columns
1 | ABC | 20/07/2012
[code].....
basically 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.
I was working on some code in VB.NET 2008 and somehow got a bunch of new functions to pop up in intellisense on a datarow array. I saw find, findfirst, sort, average, and lots more. They had an icon next to them in intellisense when I saw them. Then I went and changed some of the code and now I can't get them to come back. I have used 2005 and 2003 for a long time, but still pretty new to 2008.
View 1 RepliesWe are doing a query against an in-memory collection of LINQ data objects. The wrinkle is that we are ordering by a column in a related table whose records have not necessarily been loaded yet (deferred loading:)
Dim oPkgProducts = _
From b In oBillPkg.BillProducts _
Where b.Successful.GetValueOrDefault(Common.X_INDETERMINATE) = _
[code]....
Here is an example of my xml doc:
<?xml version="1.0" encoding="utf-8"?>
<employeedata>
<employee>
<firstname>Bob</firstname>
<lastname>Anderson</lastname>
[Code]...
However, only the first phone number (Office) displays in the listbox. The phoneinfo collection has both <phone> elements, but the For Each statement doesn't seem to iterate thru.
I have a list(of t) and I got a iqueryable(of a)
I want to filter out any item from the iqueryable(of a) where a.id = t.myotherid
I'm not really sure how to write this query[code]...
In my application, I have a search query textbox (txtSearch) that works well with one-word queries with the following LINQ:[code]So how would I make the above query more generic (ie: able to handle any number of words in a query)?I should note that the object being queried is a List of strings pulled from an Access database. As it stands, this application only queries the database once and I'd like to keep it that way if possible.
View 3 RepliesCan I use LINQ to return an item in a collection that is the same TYPE as the items in the collection? I am a LINQ Noob trying to avoid looping.
Dim mostRecentlyCreatedQuestionnaire As ParentQuestionnaireItem =
CType((From P In questionnaireCollection Order By P.Metadata.CreateDate Descending).Take(1), ParentQuestionnaireItem)
I get an "unable to CAST" error when I include the CTYPE function. I kind of expected that error, but I imagine that if I coul dnot do this, LINQ's usefulness would be diminished and therefore assume that there must be a way..
Given a simple DTO (AccountExpiry) with properties of 'AccountNo' and 'ExpiryDate' and a List of same created thus:
New AccountExpiry(123, New Date(2012, 4, 1))
New AccountExpiry(123, New Date(2012, 4, 2))
New AccountExpiry(123, New Date(2012, 4, 3))
New AccountExpiry(124, New Date(2012, 4, 2))
New AccountExpiry(124, New Date(2012, 4, 3))
New AccountExpiry(124, New Date(2012, 4, 4))
How do I use LINQ to retrieve the most recent entry per account. I have a feeling this will involve GroupBy and FirstOrDefault. It seems like...
From Item In Source Group By Item.AccountNo Into Group
Should return all of the data grouped appropriately, but It is unclear how I might apply .FirstOrDefault to each group.
I have a Dynamic DataTable Created at runtime. The Setup is like so
Id | Name | Age
-----------------
3 | Mike | 21
6 | John | 43
8 | Sara | 34
What I am trying to do is come up with a linq statement I could use to find and update specific rows.
Such as a statement to change AGE to '33' WHERE ID = '3'
My code So far is:
-[VB.NET]-
Dim MyRow As DataRow = From column In MyTable.Rows Where column("Id") = 3
MyRow(0)("Age") = 33
But this is not updating my DataTable entry.
I tried the following code:
Dim T5NHCEDCavg As Double
qry = From employee In empList
Where employee.HCEDC = False And employee.X5 = False _
Select employee.DCFSA
T5NHCEDCavg = qry.Average
But I'm getting a design-time error that says "Overload resolution failed because no accessible 'Average' accepts this number of arguments." I realize that I'm missing an overload here, but I'm not sure what to use or how to do this. I'm pretty new to LINQ. I've got a dataset in memory that I'm querying, and there is a double-precision property DCFSA, of which I'm trying to get the average based on my query above.
I've been assigned a homework assignment where I need to use LINQ to find certain numbers within an array. I've read through the book and some online tutorials, for some reason I just can't seem to understand it. I'm not asking anybody to do my homework for me... Just asking if anybody could explain it better, maybe in more detail?
View 2 RepliesFor example, there are a lot of item in ListBox..so, how can i find the certain item that i need.. Let the item in ListBox as below
1234567899
9987654321
6666666666
8908899889
8678678768
5467676767
so, how can i find 6666666666 without using the scroll bar at ListBox
I have a parent child collection objects and was wondering how to get a single item from the child collection using Linq
[Code]...
way to write the LINQ query. The parent class is simply a student's name and a list of test score data. The child class is a single test score datum. I want to find the worst (or best) score out of all of the TestScore values and then identify the student who had the best score.
Dim query = From s In studentList _
Where s.ScoreList.Select(Function(d) d.TestScore).Min _
= studentList.SelectMany(Function(g) g.ScoreList).Select(Function(h)
[Code].....
I have a generic list - SupportedTypeGroups. Each SupportedTypeGroup has SupportedTypes property (generic list of SupportedType). How to construct a Linq query to locate SupportedType with required name?
View 3 RepliesI need to mdify the code below to capture all files in all directories and write them to a grid
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
get files from current directory
Dim Files = From file In My.Computer.FileSystem.GetFiles(CurDir)
[Code]...
I have a table with the below structure.
ID VALUE
1 3.2
2 NULL
4 NULL
5 NULL
7 NULL
10 1.8
11 NULL
12 3.2
15 4.7
17 NULL
22 NULL
24 NULL
25 NULL
27 NULL
28 7
I would like to get the max count of consecutive null values in the table.
I am learning Linq, so bear with me. I have a class object that holds 4 other class objects with each holding a List(Of T) of the next. Think tiered classes. As these lists as built I need to search all the Group2 for all Group3 to see which Group3.units.count is the largest. "units" being a List(Of T). [code]
View 4 RepliesFor a class project I am supposed to search through the attached file, and write to a new file the years between 1789 and 2009 that are not present in the fifth field. What is my best bet for determining what years are not present?
[Code]...
Should I make an array of integer between 1789 and 2009, then search for every year in the file, then set a flag to false if not found; is there a simpler way to accomplish this using LINQ?
how will I find an item that's in the combobox that everytime I pressed the keyboard it will be automatically displayed in the combobox?for example I have Items like cats,pigs,dogs in the textbox then when I press d or do the Items dogs will be displayed.
View 2 RepliesI have created collection and adding values in the collection, later I need to find if uer passed value is exist in the collection or not, I use contains finction to find the answer but it always returns false even though user passed value exist in the collection list. here is my code:
[Code]...
I have a specialized string dictionary of (string, string) (_RulesAndTheirDescriptions) that contains the name (key) and description (value) of methods in a given class. I currently do the following query to search for a match on the key or value and then bind that to a grid.
[Code]...
This question is very similar to a previous question of mine, Use LINQ to count the number of combinations existing in two lists, except with some further twists.
I have a list of CartItems that can receive a discount based on the items specified in the list of DiscountItems. I need to be able to pull out the items in the Cart that can receive a discount and apply the appropriate discount specfied in the DiscountItem. The discount is only applied for each combination that exists. Here's what the two lists might look like to before the discount is applied[code]...
I am having so trouble with the ToUpper() procedure with strings. I am using LINQ to find unique values in a list of objects. In that whole process I set the values to compare to all lowercase in order to get a proper list. My goal is to populate a dropdown list with the values. I'm attempting to set the first letter of of the string to uppercase and keep the rest lowercase however the toUpper() procedure is not working?
Private Function FixCase(ByVal strIn) As String
Dim strOutput As String
Dim intStringLength As Integer = strIn.Length - 1
strOutput = strIn.Substring(0, 1)
[code].....
I have two datatables with similar structures that I want to make one existing row to be updated from another datatable.
For example, "tableA" has three columns: "one", "two", and "three"; with "one" being the primary key...
and "tableB" has three columns as well: "one", "two", and "three"; with "one" being the primary key.
Say there is a row on tableA that is different than a row on tableB (with a matching primary key). What I wanted to do, as efficiently as possible, is to take the that row from tableB and replace the one on tableA so it'll be modified.
I'm not sure if there's an easier way of doing that instead of using loops for setting the row's items.
If I have four items in the listbox, e.g. a, b, c, d, how can I find the name by knowing from the top the item is number 3 (c)?
View 6 Replies