Detemine Sequence Has Items And If So Return Value In LINQ?
Jun 7, 2011I currently do a lot of checks like so [code]...
however this results in two db hits. (one to determine if any and then one to calculate the sum.
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Use Linq ToDictionary To Return A Dictionary With Multiple Values In The Dictionary Items?
Jan 25, 2010I want to group items from a linq query under a header, so that for each header I have a list of objects that match the header title. I assumed the solution would be to use ToDictionary to convert the objects, but this allows only one object per "group" (or dictionary key). I assumed I could create the dictionary of type (String, List Of()), but I can't figure out how to write it. As an example I have written a simplified version below.
[Code]...
LINQ To XML - Sequence Contains No Elements
May 25, 2011I have this XML
<?xml version="1.0" encoding="utf-8"?>
<root>
<xsd:schema id="root" xmlns="" xmlns:xsd="[URL]" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
<xsd:import namespace="[URL]" />
<xsd:element name="root" msdata:IsDataSet="true">
[Code] .....
And I also have this method, where I take two files and take some values from them, and then I merge all the values into an object in the second query:
Public Shared Function RetrieveTranslation(ByVal filefrom As String, ByVal fileto As String) As List(Of clsTranslation)
Dim valuefrom = (From l In XElement.Load(fileto).Elements("data") Select l.Element("value").Value).FirstOrDefault
[Code] .....
So, the problem is that when I run the code, there is an "Sequence contains no elements" error in the first query(valuefrom). I debugged and it says that there is nothing in the query, but I don't understand why? I'm curious to know if it is well done to do something like I did, create an object from two queries, putting the first value in the second query.
Insert Listview Items Value In Datagridview With The Same Sequence?
Feb 13, 2011I am using visual basic 2008 and i have a listview which have 3 column like ProductCode,ProductName and ProductPrice and also a datagridview columns like ProductCode, ProductName and Product Price and a button control named Add Product. Now i want to insert Listview items value in Datagridview with the same sequence how does it. how to insert items from listview to Datagridview in the same order.
View 1 RepliesDetemine If EXE Is X64 Or X86?
Mar 13, 2012I am writing a utility that converts an application on a system to another version without the need to re-install. However the action is dependent on whether or not the existing installation on the machine is either x64 or x86.
In researching online through the many VB.NET pages I keep finding "How to determine if my EXE is x64" but this is not what I am looking for. I am looking to find whether or not an executable is compiled 64bit or 32bit.
In this directory there is also a collection of DLLs that may assist in determining this. If checking an executable is not possible.Additionally, in the event that anyone asks, determining if the OS is x64 or x86 does not help. It needs the be the files directly.
VS 2008 - Linq Statement To Go Through A Dropdown Menu's Sub Items And Get What Items Are Checked
Apr 8, 2010I have the following linq statement to go through a dropdown menu's sub items and get what items are checked: vb Dim UnselectedItems = From xItem As ToolStripMenuItem In tsiSelectObjects.DropDownItems Where TypeOf xItem Is ToolStripMenuItem AndAlso CType(xItem, ToolStripMenuItem).Checked = False
I get this error tho: Unable to cast object of type 'System.Windows.Forms.ToolStripSeparator' to type 'System.Windows.Forms.ToolStripMenuItem'. As you can probably guess i have ToolStripMenuItems and separators in there
However the AndAlso should short circuit in the case where the item is not a ToolStripMenuItem and it doesn't seem to be doing so (as TypeOf xItem Is ToolStripMenuItem=false in this case)?
Using LINQ To Return Element In Collection, Would Like To Return Nothing If Element Not Found?
Mar 3, 2011I would like the following function to return Nothing if the element with the specified key is not in the collection. Instead, it returns an error - something to the effect of "no element found"
Public Class MyCollection
Inherits System.Collections.ObjectModel.Collection(Of MyType)
Public Function FindByActivityKey(ByVal searchValue As Integer) As MyType
[code]....
How To Return Firstchild Value In LINQ
Apr 20, 2012Using LINQ, How do I only get the author element value for the following XML: [code]but n.value returns the author and all the child element values.
View 3 RepliesReturn Max Value With LINQ Query?
Nov 3, 2011I have a method that takes in an id, a start date, and and end date as parameters. It will return rows of data each corresponding to the day of the week that fall between the date range. The rows are all doubles. After returning it into a DataTable, I need to be able to use LINQ in VB.NET to return the maximum value. How can I achieve this? Here is the initial setup?
[Code]...
Use Linq To Return A Row In A DataTable?
Jan 24, 2012Currently, I am using a loop to find the row I want to update.
Public Sub pubsub_SetUserDGVColumnWidth(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewColumnEventArgs)
' update all user settings for the given column
[Code]....
Return LINQ Results From Function?
Jun 10, 2012I'm trying to return a single object from an array of objects with linq.[code]...
View 2 RepliesVS 2010 LINQ Null Return?
Dec 2, 2011I'm having trouble figuring out what to do with the bolded part, when there are no nodes to return.If there are no image tags inside the <images> tag, i get an "Object reference is not set to an instance of an object".I have been searching and searching for an answer but can't find one.
Dim orders = From o In xmlLinq.Descendants("order")
Select New With { _
.orderID = o.Attribute("id").Value, _
[code].....
Asp.net - Return Two Tables From A Stored Procedure From LINQ To SQL?
Aug 4, 2011I have written a stored procedure like this:
CREATE PROCEDURE [dbo].[TestProcedure]
AS
BEGIN
SELECT TOP 1 CampaignID FROM Campaigns
SELECT TOP 1 ServiceID FROM Services ORDER BY ServiceID desc
END
In my .NET Project, I have a LINQ to SQL file (.dbml) and I have drag-and-dropped this procedure to create a new class TestProcedureResult:
Partial Public Class TestProcedureResult
Private _CampaignID As Integer
Public Sub New()
[Code]....
So it is not returning ServiceID. How can I retreive ServiceID using LINQ to SQL? I know we can customize stored procedure calls, but how can I customize in this particular scenario?
How To Return Binary From DB Using LINQ To Display In Browser
Apr 1, 2009I am trying to return a binary from the DB using linq for display in the browser. The method below using ado.net works but I am trying to ypgrade to linq but the linq version returned the error.
Public Sub ProcessRequest(ByVal context As System.Web.HttpContext)
Dim imageId As String = context.Request.QueryString("id")
Dim ret As DataTable = Nothing
ret = DPGetImageData.GetImageById(Convert.ToInt64(imageId))
For Each dt As DataRow In ret.Rows
For Each c As DataColumn In ret.Columns
[Code] .....
IEnumerable.where In Linq How To Get Obj&return Value Of Othr Func
Apr 4, 2012How to give another function's returned value in LINQ Ienumerable.
Private function GetFruitColor(fruit) as string
'It returns fruit color.
'If valid fruit and color not available, it returns ""(empty string)
[code].....
'Below code is wrong. but please suggest me how to correct it. My intention is, I want output collection(say dictionary) of each fruitname and its color(returned by other function call) for all the fruits which the GetFruitColor is not nothing(it can be empty or valid string).
Dim query = _
fruits.Where(Function(fruit) k= GetFruitColor(fruit) if not k is nothing select fruit, k)
End Sub
Is There A Native LINQ Way To Return A Typed Collection
Apr 18, 2011Is this the most straight forward way to return a typed collection?Here's the key line of code which returns a implicit type of IEnumerable that used to manually loop through to manually recreated a TYPED collection. Is there any native LINQ way to return a typed sorted collection without this recreating of the collection? [code]
View 2 RepliesLinq Return Results Contaiined In A List?
Mar 23, 2011How can i select using linq from a datatable where the the only results I want back (ID's) are contained in a list of integers?
View 7 RepliesReturn Column Names Of A LINQ Entity?
Feb 2, 2011I am using LINQ to SQL queries to return data in my application. However I find it is now needful for me to return the column Names. Try as I might I have been completely unable to find out how to do this on the internet.
So if my LINQ entity table has the properties (Last_Name, First_name, Middle_Name) I need to return[code]...
Return Max Record Count By Grouping In Linq?
Nov 9, 2011I'm very new to linq and I'm trying to come up with a linq query against a dataset that will return a max count value based on grouping records.[code]...
View 1 RepliesReturn Type For Collection From LINQ Query?
Oct 15, 2010I have a method, that returns a group of accounts
Public Shared Function GetAllNotesByUser(ByVal UserID As Guid) As Account (??)
Using db As New MyEntity
Dim query= (From A In db.Account _
[Code].....
I would then like to pass this to another function to calculate the totals for all the accounts in the collection. Is it best practice to return an Ienumerable, a generic list, I'm just not sure what works best with LINQ and the entity framework.
Using LINQ To Return First Item From Each Set Of Grouped Data
Apr 16, 2012Given 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.
LINQ Objects - Group All The MyObjects Together That Share The Same Value And Then Return That Value?
Nov 16, 2010I am having trouble following some of the examples at MSDN for LINQ.Basically I have a List Of MyObject. MyObject has a property called Value which is an integer.I want to group all the MyObjects together that share the same Value and then return that Value where the count of the group is greater than 5.I have tried the following,
dim foak = From o as MyObject in MyObjectList _
Group o By o.Value into Count _
WHERE Count > 5 _
Select o.Value
LINQ Stored Procedure Return Value To A String Array?
Mar 24, 2011I have a stored procedure in DBML and I try to pass the result to "sqlQryArray" as an array(1 dimensional array). But the bottom code causes error like below message. What else should be done?
Error 1 Value of type '1-dimensional array of aaaDatabase.stp_GetSomethingResult' cannot be converted to '1-dimensional array of String' because 'aaaDatabase.stp_GetSomethingResult' is not derived from 'String'.
The return result from stored procedure is a just list of first names of students(only one column)
Dim sqlQry = aaaLINQ.stp_GetSomething(bbb,ccc,ddd)
Dim sqlQryArray As String() = sqlQry.ToArray()
LINQ Return Single Type Of Object Invalid Cast
Jun 29, 2010Ok, just needing a 2nd set of eyes looking at this to make sure the error isn't something else other than my LINQ code here. Here's the function class itself:
Public Function GetJacketByPolicyID(ByVal jacketID As Int32) As tblPolicy
Dim db As New DEVDataContext()
Dim j As tblPolicy = db.tblPolicies.Single(Function(p) p.policyNumber = jacketID)
Return j
End Function
and here is the code which calls this class function in the web control form itself:
Dim p As tblPolicy
Dim j As New Jackets()
p = j.GetJacketByPolicyID(3000050)
For some reason it's flagging the 2nd line in the GetJacketByPolicyID function saying the specified cast is not valid. So I'm guessing it's something I'm doing wrong. I'm sure the tblPolicy/tblPolicies class works right since I can create a new instance of a tblPolicy and set a few variables by hand and return it, so that's not it. I've also checked the datarow I'm fetching and there's no null values in the record, so that shouldn't be it either.
Linq To SQL - How To Return Values For A Single Date In Datetime Format
Nov 30, 2011I am trying the following to select a long date, but becase the value is stored in SQL database as DateTime I am unable to return any results unless minutes and seconds match perfectly...I then tried to use 2 calendars and have the same issue with the DateTime format..
CODE:
Using LINQ To Query XML And Return Empty String If No Data Is Present?
Mar 8, 2011What I'm trying to do is to write a generic rss reader that I plug in any URL into without worry if the feed has all the common properties. For instance in my example below I'm looking for pubDate, however if no pubDate exists in the xml I'd like to return the current Date. I cannot seem to get the syntax right though.
Dim xmldoc As New XDocument
xmldoc = XDocument.Load(url)
Dim feeds = From feed In xmldoc.Descendants("item") Select New With { _
[code].....
VS 2008 - LINQ Query Against A Typed Datatable That Will Return Me Duplicated Data?
Jan 25, 2010I'm trying to do a LINQ Query against a typed datatable that will return me duplicated data.With out going into too much detail, here's the basic setup:
strCode1 - string type
intCode1 - int32 type
intAdjustor - int32
There are more fields but these are the ones that are important.I'm going to do my best to describe this, as it's kind of confusing.In theory intCode1 is a key for strCode1 (hence the names). So each time intCode1 is duplicated, the same strCode1 should appear. Example:
[code]...
Ultimately I'd like to get a List(Of T) - where T is my typed data row. In SQL, I would simply use a sub query, to get a distinct list of strCode1 and intCode1, then do a count, grouped by strCode1 where I get more than one row.I'm not sure how to translate that into LINQ, AND get the original types data rows returned in a list.
ListView.SelectedItems Doesnt Return The Actual Selected Items?
Dec 10, 2010As the title describes I tried to get the selected items and it returned an emtpy collection. The property only works once after that something goes wrong and it returns an emtpy collection. Does anyone know why? Or knows what I'm doing wrong?
View 6 RepliesC# - Pick Out A Group Of Items Using Linq To Xml
Jul 4, 2011My head is fuzzled with this. I have an xml doc which has the layout for a grid stored in it. If you notice the columns are stored as "Items" in the XML. I am trying to retrieve each "Item" out of the XML using LINQ but no matter what I do I keep taking on straggler properties that I don't need.
[Code]...
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