Use LINQ To Query The Items Collection Of A ComboBox?
Jul 14, 2011Is it possible to use LINQ to query the items collection of a ComboBox & get the index of the item that matches what I'm looking for?
View 4 Replies
ADVERTISEMENT
Return 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.
Linq Query To Compare If Collection Contains List Of String?
Feb 3, 2012I am using a path comparison to find any children tags which works well when there is only 1 tag selected. This is my code for when multiples tags are selected but it is not working. Can you point me in the right direction?
Single Tag Selection (working)
Dim tagpath = uxTags.SelectedItem.Text
lnqCases = From i In lnqCases Where i.HelpDeskTagItems.Any(Function(x)
[code]...
Cannot Iterate Of A Collection Of Anonymous Types Created From A LINQ Query?
Mar 17, 2010Every LINQ example I have seen for VB.NET anonymous types claims I can do something like this:
[code]...
Now when I go to iterate through the collection(see example below), I get an error that says "Name "x" is not declared. For Each x in Infos It's like VB.NET doesn't understand that Infos is a collection of anonymous types created by LINQ and wants me to declare "x" as some type. (Wouldn't this defeat the purpose of an anonymous type?) I have added the references to System.Data.Linq and System.Data.DataSetExtensions to my project. Here is what I am importing with the class:
[code]...
C# - Linq To XML Query Creating Empty Items From XML
Feb 15, 2010why is this xml
<?xml version="1.0" encoding="utf-8"?>
<items>
<item id="77" cityID="EE12345" cityDatum="15.2.2010. 11:28:35" />
</items>
[Code]....
If you, as some can't replicate these results, here's a screenshot:
.net - LINQ Query For Filter By Selected Items In Checkbox List?
Jun 30, 2011Could not find this through Google or in SO questions.I have a checkbox listbox on my form. I want to filter my List by the list of selected Ids from that listbox that are checked, in SQL I would have done this like "Where TypeId In (1, 4, 5, 7)"... how do I do that in LINQ?
I feel like I am missing a really obvious answer, but cannot get it.
For argument sake... here is the what I have for sample data:
In Colors (List<of currentColors>)
ID, Name, TypeId
1, Red, 1
2, Blue, 1
3, Green, 2
4, Pink, 3
Selected Types 2 and 3 in CheckboxList: filteredColors
[Code]...
LINQ To SQL Query - Select Customer From Dropdownlist And Then Gridview - Load All Items Of All Orders Of That Customer
Oct 4, 2011I have the following problem: I select a customer from a dropdownlist and then the gridview should load all items of all orders of that customer. I have the following query:
Dim allorders = From ord In db.Orders
Where ord.CustomerID = Convert.ToInt32(CustomerDropDownList.SelectedValue)
[CODE]..............
I also tried to modify the query as follows:
Dim orderitems = From oi In db.OrderItems
Where oi.OrderNumber = (From From ord In db.Orders
[CODE]...........
But this does not work. I just started using LINQ.
LINQ Query Is Enumerated - Turn On Some Kind Of Flag That Alerts Me Each Time A LINQ Query Is Enumerated?
Sep 22, 2009I 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.
.net - Search The Collection Of A Collection In LINQ Where Clause?
Apr 15, 2009I've got the following ADO.NET Entity Framework Entity Data Model:I want to find all the Policyholders with both a Service of a given Id and also a Keyword of a given Status.
This LINQ Does Not Work:
Dim ServicesId As Integer = ...
Dim KeywordStatus As Integer = ...
Dim FoundPolicyholders = From p As Policyholder In db.PolicyholderSet.Include("Keywords").Include("Services") _
Where p.Services.Id = ServicesId _
And p.Keywords.Status = KeywordStatus _
Select p
The Where clause cannot search the p.Services and p.Keywords EntityCollections in that way.
[Code]...
Search The Collection Of A Collection In LINQ Where Clause?
Apr 15, 2011search the collection of a collection in my LINQ Where clause?
View 11 RepliesAccessing And Adding Items To A Collection That Is In A Collection?
Apr 6, 2012currently in my application I have a Global Collection that is a Collection of Collections.Currently I am trying to add items/ elements to one of the child collections of the Global Collection but I am unable to use the collections methods of the child.When I assign a variable to the child collection and return the collection it is just an object with the collection inside.
Ex:
Dim GlobalCollection as New Collection
Dim ChildCollection1 as New Collection
Dim tempCurrentCollection[code]......
.NET LINQ - Count Of Collection Within Collection?
Apr 14, 2011Take the following scenario:
Public Class Store
Public Overridable Property Areas As List(Of Area)
End Class
Public Class Area
[code]....
What's the quickest way to get a total count of shelves for a store? I.e. for a store I get the total count of areas by using Areas.Count Or will I need to loop through each area and tally the count of shelves?
.net - ActiveRecord Linq/NHibernate Linq Not Building Query Completely?
Jul 14, 2011given this function:
Public Function Search(ByVal StartIndex As Integer, _
ByVal MaxResults As Integer, _
ByVal AccountNumber As String, _
ByVal LastName As String, _
[Code]....
instead of what I expected:
Select count(*) from remitline where lastname = "smith"
What am I doing wrong building up the where clause? I'm using Castle ActiveRecord 2.1
Performance Gain In LINQ Query Vs LINQ Stored Procedure?
Aug 6, 2009if there is that much of a performance gain in running a LINQ stored procedure versus a LINQ query?
View 1 RepliesAsp.net - Complex Linq Query - Add A .Where() Or .Any() Predicate To Reduce Query Complexity (in VB)?
Sep 14, 2010I 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
[code]....
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)?
LINQ Query Using The Dynamic LINQ Library?
Mar 31, 2011Forgive 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."
"System.ArgumentException: An Item With The Same Key Has Already Been Added." When Trying To Order An In-memory LINQ Query By A LINQ Association?
Jan 27, 2011We 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]....
LINQ To SQL - Add In Row_Number To A LINQ To SQL Query?
Aug 31, 2011How do I add ROW_NUMBER to a LINQ query or Entity? How can I convert this solution to VB.NET?
[Code]...
I'm having trouble porting that last line. I have been unable to locate a VB.NET example. I'm actually not looking for any paging functionality like the example provides, just good old-fashioned Row_Number(Order By X) row index.
LINQ To XML, Only Can Get First Item In Collection?
Sep 8, 2010Here 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.
LINQ Where Statement In Collection?
Mar 28, 2012I have a Customer object which has a collection of ContactNumbers. Is it possible with LINQ to get a list of Customers where one of the contact numbers = '123'?
Public Class Customer
Public Overridable Property ContactNumbers As List(Of ContactNumber)
End Class
[Code].....
Dynamicaly Refresh Databound Combobox Items Based On Selected_index_changed Event Of Another Combobox?
Jan 27, 2010I am using VB.NET together with ADO.NET to create a program. I have set my TableAdapters as needed and bound the correct tables-columns to my comboboxes.My problem though is this:My combobox2 item is bound to a datatable. The table adapter's Fill method (the select command basicaly) includes a public variable in the where clause to fetch the correct results. I ll put some code here to clarify it a bit more.Public Class Frm_inv
[Code]...
Get All Items From One Column Of Database Table To The Combobox Items
Apr 28, 2012I want to get all items from one column of database table to the combobox items.
View 2 RepliesBuild A String From A Collection With Linq?
Oct 8, 2009I'm building flat file content from collections of strings.
Example collection: A, B, C, D, E, etc.
I want to be able to output these values to a string with line feeds in one swoop with Linq if possible.[cod]e...
Get Last Instance Of Collection Controls Using Linq?
Mar 6, 2012How to get the last instance of label control in List (of Control) using linq?
View 4 RepliesLinq Iterate A Control Collection?
Jun 29, 2009Private Function GetWebDataGridOKButtonId() As String
Dim ctls As ControlCollection = _
WebDataGrid1.Controls(0).Controls(0).Controls
[Code]....
This is not working for me. I am trying to iterate a control collection and return one control ID.
VS 2008 Linq Possible To Use Query In Another Query?
Apr 16, 2011I was wandering is it possible to use a query within another query below is the code I am trying to use.
Public Function GetInventByComp(ByVal CompID As String) Using DC As New DataClassDataContext
'need to get company id's based off names? thats bad should be name from Id need to rethink this
Dim invent = (From C In DC.Inventors_Companies _
Where C.CompID = CompID _
Select C.InventorID).ToString
[Code]...
I was trying to us multiple values in a string like "1, 3, 5" but I can't seem to get that working either so I am trying to use just a single value now. Can anyone help me? "Yes I am new to this"
Combobox.items.add - Combobox To Have A List Of Choices From A Table In A Db
Jun 14, 2011[Code]...
I'm making a combobox on a form. I want the combobox to have a list of choices from a table in a db. The two columns are a String and a Date. I want the date column to only show the year. I'm hoping I have the code right as it is above, but I'm not positive I've done the whole date thing right.
Filtering A Collection With Linq And Multiple Criteria?
Jun 7, 2012On my view there is a datatable holding a collection of ServerRow and 4 textboxes (Hostname, OS, Location, Zone). When the user types into any of the 4 boxes I want to immediately filter this list. I have this code setup and ready to go that on the set method of each textbox property I call the filter method.
Now onto the problem: if I have 4 criteria that means I have 2 to the power of 4 different scenarios. What I would like to do is write a linq statement with all of these scenarios dealt with such that if any of the properties are NullOrEmpty they will not be used in the Where clause and on the flip side if there is a value the corresponding field will be searched with a Contains.
Example
AvailableCis = New ObservableCollection(Of ServerRow)
(_CiData.Where(Function(ci) ci.OS.ToUpper
.Equals(_selectedOS.ToUpper) AndAlso
ci.HostName.ToUpper.Contains(_ciNameFilterText.ToUpper))
.OrderBy(Function(a) a.CiName))
This example shows how it works with 2 criteria and both of those criteria are set.
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 Replies