I can achieve in VB what the following C# snippet does but it seems very clunky since I perform a Linq query to obtain the events for the relevant user. Is there a neat way?
ctx.FetchEventsForWhichCurrentUserIsRegistered((op) =>
{
if (!op.HasError)[code]........
I'm using a DataGridView to post the results of LINQ-from-SQL query. I was hoping that the data would be editable in the DataGridView, but it isn't. I made sure that DataGridView.readonly = false. I'm using VB.
VB 2008
DB = New CXToolDataContext()
Dim Systems = (From TBLSYSTEMS In DB.tblSystems, TBLSYSTYPES In DB.tblSystemTypes _
Where TBLSYSTEMS.ProjectName = projectnumber And TBLSYSTEMS.SystemType =
[Code]...
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'm attempting to make a generic query executer function. I want to be able to send it a query string and have it return a two-dimensional array containing the results. Below is my code for how to do it with a (9,x) array. How can I do it with an (y,x) sized array? Also, I feel like there must be a more efficient way to do this..
[Code]...
I've been reading the official DNS RFC [URL].. and looking at articles like this that explain how DNS query packets are structured [URL].. but I'm having a hard time trying to combine the two and actually get to a point where I know what to do
Basically I know that I need to use UDP to send the query and there is only one type of query I actually want to perform - an MX lookup. So I'm hoping that means I dont need to account for a lot of things that anyone creating a complete DNS Resolver would need to implement.
The only experience I have with network communication like this is with protocols that are text based (and use TCP, but I dont think that makes much difference here, if anything UDP should be easier). DNS however is binary based and I just cant figure out how I would know what bytes to send down the wire for a specific MX query..
I wish to output an IEnumerable type (dictionary(of T) would be perfect, otherwise a datatable would be acceptable) that provides an aggregation of the data within the datatable.In SQL I would write the query as such: select groupByColumn, sum(someNumber) from myTable group by groupByColumn
In VB.NET the closest I have got to this (achieved using information here) is: dt is a datatable containing two columns, referred to by index in p below Dim q = From p In dt Group p By p(0) Into Sum(p(1)) Select p(0), SumOfNumber = Sum
However I receive error: "Range variable name can be inferred only from a simple or qualified name with no arguments." on the p(0) element. Therefore my question is as follows:How can I resolve this error? How do I process the result (q) as an IEnumerable type? Life isn't made any easier because I'm using Linq in unfamiliar vb.net. Many examples are in C#, but I haven't really come across anything suitable even in C#.
I have created a SELECT FROM WHERE query to perform a search here is my code:
SELECT EmployeeID, DepartmentID, Forename, Surname, Role, Email, Telephone, Extension, Mobile, Photo FROM Employees
WHERE (Forename = ? or ? = '') and (Surname = ? or ? = '') and (Role = ? or ? = '')
I have then put the folllowing code to rung the query within my form:
Me.EmployeesTableAdapter.FillByName(Me.myDataSet.Employees, Me.ForenameTextBox.Text, Me.ForenameTextBox.Text, Me.SurnameTextBox.Text, Me.SurnameTextBox.Text, Me.RoleTextBox.Text, Me.RoleTextBox.Text)
When i search by forename or surname it works fine but when i search by role i get this error..oledbException occured No value given for one or more required parameters.
How do I perform an sql query onto a DataTable not a Database table?
View 1 RepliesIn my company we use Oracle Applications. Almoust every form in these applications have a common behaviour, which is:
Whenever the forms is opened one can immediately start entering data but one can also press F7, which makes the form to enter in query-mode. You can then fill one or more forms fileds with the data you are searching for and press F8, which executes the query and returns the data into the form. The query mode can be interrupted by pressing Ctrl+Q, returning to data entry mode.
My question is if there is a way of having similar behaviour on building VB forms. I'm using VS 2010.
How can i perform order by tCount in this Query?
Public sub StatReport()
Dim Transaction = xmlDataset.Tables("ebus_transactions")
Dim TranCounts = From T In Transaction Take 2 _
[code]....
Is there a way to obtain the current user credentials that are being used for VPN access? [code]
View 1 Repliesgiven 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
if there is that much of a performance gain in running a LINQ stored procedure versus a LINQ query?
View 1 RepliesI 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]....
I want to know if it is possible to perform a mySQL query to get a single record (searched for by ID) and then split each field into a seperate text box.I think im ok with the SQLQuery to get the record. its the splitting it into individual text boxes that im strugling with.
View 1 RepliesForgive 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."
When i upload my site in aspspider.com then it shows the following message.I use default dataase of asp.net namely ASPNETDB.MDF
Server Error in '/dobriyal' Application.User does not have permission to perform this action.Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: User does not have permission to perform this action.
Source Error:
Line 7: Dim cmdSelect As New System.Data.SqlClient.SqlCommand("SELECT Password FROM a1_admins WHERE EmployeeId =" & TextBox1.Text & " And Email = '" & TextBox2.Text & "'", SQLData)
[code]....
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) = _
[code]....
How 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.
I have built a webcrawler where I use a webbrowser control for a user to enter a url and perform a search. Once the page is uploaded, my app grabs the HTMl and then with a button click convert it into plain text by using html agility pack (HAP). Finally by clicking a button I store the result inside a sql server database.
Now I want to use a background search system using the above control to perform the task which I am not able to figure out Basically say If I have a textbox where I enter the URL and it grabs the HTML then using HAP I have convert it into plain text and store it inside a database.Here is my code class for the normal search I carry out:
[Code]...
I have DataTable, and is bound to DataGridView. So, when the user inputs some values in 4 columns, it would calculate the sum and put it in the last 2nd last column.
Here's the code that I'm experimenting:
vb.net
Private Sub DataGridView1_RowLeave(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.RowLeave
Dim i As Integer
Dim intTotal As Integer = 0
For i = 5 To DataGridView1.Columns.Count - 3
[Code]...
So, basically it should sum up certain columns when the user enters numbers into it and then display it in the last column.
I 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"
I created a control that has picture box control docked within it. This control allows me to "animate" the image by swapping them out by setting the interval to swap them at. I want to use this control kind of like an animated icon within a application, but because the picture box is docked, the control I created won't respond to the events, MouseHover specifically. [Code]
View 2 RepliesI have the following SQL:
[Code]...
I want to put it (the select count statement) in this LINQ statement so I can get the sales count in my linq statement: Dim TheLeads = (From L In DB.Leads Where L.IsDeleted = False Select L).ToList() Is this possible to do in LINQ?
The Random generator works fine. What I have a problem with is adding the rows and columns.
Array
0,0 0,1 0,2 = row total
1,0 1,1 1,2 = row total
[code]....
I've been reading a fair bit about the performance of using LINQ rather than using a for each loop and from what I understand using a LINQ query would be a little bit slower but generally worth it for convenience and expressiveness. However I am a bit confused about how much slower it is if you were to use the results of the query in a for loop.
Let's say that I have a set called 'Locations' and a set of objects called 'Items'. Each 'item' can only belong to one 'location'. I want to link items that are under the same location to each other. If I were to do this using a normal 'For Each' loop it would be something like this:
For Each it as Item in Items
If it.Location.equals(Me.Location)
Me.LinkedItems.Add(it)
End If
Next
However if i was to use LINQ it would instead be this:
For Each it as Item in Items.Where(Function(i) i.Location.equals(Me.Location))
Me.LinkedItems.Add(it)
Next
is the second (LINQ) option going to loop once through the entire 'Items' set to complete the query, then loop through the results to add them to the list, resulting in essentially two loops, or will it do the one loop like the first (For Each) option?
Is it possible to do the following? [code] Basically I have one Load_Gridview function that is called on all postbacks, and rather than creating a bunch of different cases.I want the filters to stack.My actual code has more filters set up (4 or 5 of the).It all compiles ok but when I run and try to execute with active checked, or a department selected I get the following error. [code]
View 4 RepliesI have below XML file
<?
xml version="1.0" encoding="utf-8" ?><
PageFlow>
<
attributegroup name="Search"><
attributes>
[Code]...
I am looking to sum the "Status" field.
Dim _detailRecords As New DataTable
_detailRecords.Columns.Add("y")
_detailRecords.Columns.Add("z")
[Code]....
I'm also wanting to keep this as an IEnumerable of DataRow because I will be creating a datatable from it with
Dim yyyyy As DataTable = query8.CopyToDataTable
I am Fairly new to Linq and I am trying to write a simple query to return the error messages within my xml file.
<?xml version="1.0" encoding="utf-8"?>
<Error xmlns="urn:xxxxx">
The following errors were detected:
[code].....