Just a quick question about LINQ, I want to use a value from the returned dataset to lookup a value and return this. The line I am struggling with is .ViewingNotes = NewViewing(pt.ProspectId).GetViewings().Columns(7).ToString(). Is this possible?
With BusinessLayerObjectManager.Context
Return (From p As [Property] In .PropertySet
Join pt As Prospect In .Prospects On pt.Property.propertyID Equals p.propertyID
I have the follow Linq query that is in a web application that was converted from .NET 1.1 to 3.5:
dim objListOfFilteredDataRows = from datarows as datarow in objDataSet.tables(0).rows _ where datarows("SomeColumn") = SomeValue
I have the exact same query in an application that was created using .NET 3.5 and the query returns an IEnumerable. However the query in the converted application is returning:
**Edit: When I highlight the expression, the intellisense says that it doesn't know the type of objListOfFilteredDataRows and assumes its a type of "Object". Why is the type not infered in the converted 1.1 application but is infered in the "native" 3.5?**
What am I missing here? How do I convert the "WhereEnumeratorIterator`1 to an IEnumerable?
I have got an xml document which looks something like this.
<Root> <Info> </Info> <Info>
[Code]...
How can i write a linqToXML query so that it returns me an IEnumerable containing each child element, in this case all five child elements of , so that i could iterate over them. The order of child elements is not definite, neither is number of times the may appear.
I have an array of unknown (to the current method) class objects. I do know that each class has a property called "Number". I am trying to write a LINQ query where I am looking for the object with the next Number in sequence. AKA, I'm at Number 8, use a LINQ query to find the object where Number=9.
I know that LINQ queries are deferred and only executed when the query is enumerated, but I'm having trouble figuring out exactly when that happens.Certainly in a For Each loop, the query would be enumerated.What's the rule of thumb to follow? I don't want to accidentally enumerate over my query twice if it's a huge result.
For example, does System.Linq.Enumerable.First enumerate over the whole query? I ask for performance reasons. I want to pass a LINQ result set to an ASP.NET MVC view, and I also want to pass the First element separately. Enumerating over the results twice would be painful.It would be great to turn on some kind of flag that alerts me each time a LINQ query is enumerated. That way I could catch scenarios when I accidentally enumerate twice.
I suspect I am being very silly here but I have the following setup
Class MustInherit myBaseClass 'some stuff End Class Class myInheritedClassA
[code]....
Running this results in the following error
Unhandled Exception: System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException:
[code]....
is there any way of 'Widening' the inherited class to the base class so this would work?
EDIT:regarding XmlInclude(typeof inheritedClass), currently this method could potentially return a number of types of inherited class (i.e myInheritedClassA and myInheritedClassB) is it case of simply having to add each of the inheritedTypes in this tag?
So, I'm not really sure if I have this setup properly or not. This is my first attempt at utilizing LINQ and I am trying to return data directly from an XML file.Here is my XML structure:
I have to join two main tables, and I need to filter the results by elements in an ASP.NET web form. These filters are created on the fly so I have to use a lot of where extensions to filter the query. I want to execute the query with as optimized SQL as possible.
I am first doing a simple join between TW_Sites and TW_Investigators. Then there are two sub-tables that are involved. TW_InvestigatorToArea and TW_InvestigatorToDisease. While most of the where clauses are working fine, I have found a performance issue that won't be an issue right now, but will be an issue as the table gets bigger.
The arrays DiseaseCategories and DiseaseAreas would be the results of a CheckBoxList result.
Protected Sub LoadResults() 'Get Dictionary of Filters Dim FilterDictionary As OrderedDictionary = Session.Item("InvestigatorFilterDictionary") ' Initialize LinqToSql
but when i run the query in my project the reader in not reading correctly...even if values are present is returns false and if values are not there then it returns true.
I am finding this weird issue. When I do this > activities.Where(Function(a) (Not a.IsDeleted And a.ParentId = 100) It returns an in-memory query & when I try opening it up, it throws a object not set exception. This only happens when there were no items which satisfied the condition. Shouldn't it be returning an empty set? When there are items satisfying the condition, then it returns a list & works all good.
Any best approach to what I'm trying to achieve (linq to sql, returning list of data to show in a grid/list etc etc)... Its complaining about anonymous type conversion, and from what I'm reading, thats not elegant way of doing it.
Public Function GetHistory(ByVal historyId As Integer) As List(Of ?????????) Using dc As New myDataContext(Application.GetConnection) Return (From t In dc.ActionTypes, a In t.MyTable Where a.HistoryID = historyId Select a.ActionOn, a.ActionBy, t.Description, a.ImpactedItem, a.ActionDescription).ToList End Using End Function
Forgive my ignorance on this.I have this LINQ Query:Dim ngBikersDataContext As New CarBikeWalkDataContext
bikersList = (From c In ngBikersDataContext.Reg_Bikers _ Order By c.L_Name _ Select New Bikers() With { _ .BikerID = c.BikerID, _ .F_Name = c.F_Name, _
[Code]...
with the error "Overload resolution failed because no accesible 'Select' accepts this number of arguments." Over the "NEW" I get an error " ')'expected."
I'm trying to run a query from a search form by date and I'm receiving the following error:[Teradata Database] Partial string matching requires character operands.The code for the search is:
ElseIf OptDate.Checked = True Then sSQL &= "DATE_SUBMIT Like ('" & txtDateRec1.Text & "%')" End If
I am trying to debug my code, which involves a simple webservice that passes parameters to a data class, which calls a stored proc, and returns one row of record. I am not getting any error messages, but I am not getting any records back either.[code]
I am developing an application that based on when a user has last entered a payroll, my program tells them the next available Sunday that is available to them based on
1. The date that the last time payroll was entered
2. If payroll ran = "yes" or "no"
I have a sql query that returns the next Sunday back to me based on this criteria, but when I put it into my application, it returns 1/1/0001 to me.
Here is the query: select MAX(payrolldate) AS [payrolldate], dateadd(dd, ((datediff(dd, '17530107', MAX(payrolldate))/7)*7)+7, '17530107') AS [Sunday] from payroll
I am building an application where a button click runs a sql query and shows a user the next available date that they can process from. The problem was that it needed to be the following Sunday and not the following day.
That code looked like this:
Public Class Form1 Dim ReturnValue As Object = Nothing Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
I am building an application where a button click runs a sql query and shows a user the next available date that they can process from. The problem was that it needed to be the following Sunday and not the following day.That code looked like this:
Public Class Form1 Dim ReturnValue As Object = Nothing Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim connectionString As String
I am using LINQ queries inside a WCF service to return data to a Silverlight frontend. Problem is the columns being returned using LINQ are in alphabetical order and I want them the way they are ordered in the database instead. Does anyone know how to stop the alphabetical ordering of column names?
I am building an application where a button click runs a sql query and shows a user the next available date that they can process from. The problem was that it needed to be the following Sunday and not the following day. That code looked like this:
Code: Public Class Form1 Dim ReturnValue As Object = Nothing
[code]....
Code:"select payrolldate from payroll where(payrolldate <= getdate())and payrollran <> 'yes'")but when I add that query it just returns a value of 1/1/000 as the date.
I have a view on some data in my database it returns the data as I would expect, for example
Call Date To From Phone Number 20/1/2010 00:00 23:59 08923233223 20/1/2010 00:00 23:59 08923233245
However when I have added this to my Entity Model and query it I get duplicate(and unexpected) data appearing
Call Date To From Phone Number 20/1/2010 00:00 23:59 08923233223 20/1/2010 00:00 23:59 08923233223
I am simply binding a Entity Data Source to this Entity but I am left scratching my head as to why the data is being returned differently
EDIT: Interestingly this can't be the result of some strange under the hood join as the row counts match as expected. I have also put together a query myself to test with the same odd results.From o In App.Entities.v_PersonalRules Where o.companyid = CompanyID Select o. I am using Visual Studio 2010, .NET 4
Im currently working on an n-layer application that does alot of database work.90% of all database queries are updates, and inserts and I want to be able to view the results of my query in the presentation layer.I was thinking of creating a QueryResult class that has a few properties like QuerySuccessful (boolean), Message (string) - holds success or error message, and optional field to hold any additional data that may need to be passed back to the presentation layer.So I guess my question is, am I going about this the correct way by creating a QueryResult class, and passing that back up through the layers to my PL?
In my code I enter a string in a text box and have the query check the server for the entry. If it exists it returns the string and the date into two separate variables. The database only has TrackingNumber and Date. Below is the code. As of right now i get "Invalid attempt to read when no data is present." at the "If (sdr("TrackingNumber") IsNot Nothing) Then" line.
Public Function CreateSqlParameter(ByVal name As String, ByVal dbType As DbType, ByVal direction As ParameterDirection, ByVal value As Object) As SqlParameter Dim parameter As SqlParameter = New SqlParameter()
We 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) = _