Using Statement With A Scalar Query?
May 30, 2012Can you show a coding example that has the "Using" statement with a scalar query?
View 1 RepliesCan you show a coding example that has the "Using" statement with a scalar query?
View 1 RepliesI am trying to write VB.NET query without writing SQL stored procs. I have already gotten many dataset text queries to work. But I am having trouble with getting this scalar query to work. All I want to do is to get the result of this T-SQL query. How can I code this successfully? select (DateDiff(w, '1/1/' + '2011', getdate())) / 7 AS SELECTED_WEEK (What this code does is it returns the current week of the year). And will this query above return the value as an integer datatype or string?
I tried your answers but it gave me this exception error:
System.InvalidOperationException: ExecuteReader requires an open and available Connection. The connection's current state is Closed.
When I type in cntrows. I get all my table variables except the one I want which is TotalComments. How do I return the Count from my scalar query? I have a Table Adapter named :
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I have Customers table in a database. I'd like to create List of CustomerNames using entity framework 4.1. How can I do that in Visual Basic?
Dim customerNames = (From c In _context.Customers
Select New With {c.CustomerName}).ToList()
brings a list of anonymous objects.
Ok im trying to do a if statement in Linq and was wondering if it was possible to do something like:
Dim loadFriends = From p In db.UserRelationships Where p.aspnet_User.UserName = User.Identity.Name _
Or p.aspnet_User1.UserName = User.Identity.Name And p.Type = 1 _
Select New With {if p.aspnet_user1.user = "a certan username" then .username = _
p.aspnet_user.username else .username = p.aspnet_user1.Username}
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In my Form1 i have a datagrid with coulmns: CarName , CarModel , CarColor , CarOwner (there are a lot of data).
I added queries (textboxes that the user writes in text) that can "filter" data when the user want to choose specific CarName or specific CarModel.
textbox1 = CarName
textbox2 = CarModel
textbox3 = CarColor
textbox4 = CarOwner
If the user writes text in TextBox1 then the data shown in the DataGrid is filtered.What if the user want to choose also (!) a carOwner? I know how to use AND statements, but if the user didn't specified a carOwner non of the data is shown although there are this kind of data.
I created a sql query to check if the mobile number is registered or not. If its registered, it will send the new pin code to the customer and if its not, the customer will get a message that "This number is not registered or you are not authorized to this"... something like that... Sending of new code is already working. I just dont know how to make it as conditional statement like PHP. After you query on PHP, you can just set a variable and make a conditional statement..Here is my script in vb.net:
Private Sub CheSMS()
Dim SQLServer As String = My.Settings.SQLServer
Dim conn As SqlConnection[code]......
How can I turn the following query into a LINQ statement? [code]
View 1 RepliesWe use LINQ to SQL extensively, and one of the biggest performance pitfalls we've run into is situations where a query can't be converted to SQL, and so an entire database table gets loaded into memory and the query performed by .NET. For example, this query
Dim Foo = (From c in Db.Contacts Select c Where c.ContactID=MyContactID)
translates to a simple SQL query, whereas
Dim Foo = (From c in Db.Contacts Select c Where c.ContactID=SafeInt(MyContactID))
doesn't because SafeInt is our own function and doesn't have a SQL equivalent; so the whole contacts table gets loaded into memory and searched by LINQ to objects, which is vastly slower. With a little experience, we've gotten better at avoiding this kind of situation. But it's not always obvious, and this is the sort of problem that's often not revealed until you're working with a lot of data and things start to slow down. Is there a straightforward way to see - whether in Visual Studio or some other way - how LINQ queries will be handled, other than trial and error?
I am getting a syntax error for the code below.I am trying to create a user in the mysql database and add their information to a datagrid control all in one button click using two statements; one to create the actual user, and one to add the user and their additional information to a table on the database and then refresh the datasource which will display the new user's information in the datagrid control.
If anyone knows where i went wrong please feel free to critique my code and let me know; or simply offer more efficient alternatives to what im hoping to achieve.
For those of you that must know, i am running the latest version of MySql server, MySql Workbench, and Visual Basic 2010 Express on a windows 7 based laptop. I'm writing this program in VB.net.
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It seems like the query builder in vb only allow 1 table to use the INSERT statement, so are there any way add more than 1?
View 2 RepliesI have three tables set up in a MySQL database called "event", "status" and "user". (as shown below:
EVENT TABLE (below)
STATUS TABLE (below)
USER TABLE (below)
and when I get data from the event table I use the SQL query statement below to bind the persons first and last names together as one variable called "name" and then bind that name to the respective user_id; and so on. However when I make changes to the event table it doesn't show the changes I've made. I'm certain it has something to do with the way I'm retrieving the data.
SELECT CONCAT(u.lastname, ', ', u.firstname) AS Name
, s.message AS Message
, DATE_FORMAT(e.timestamp,'%b %d %Y - %r') AS DateTime[code].....
I want to make a report with a query "Select * from StudMaster where StudID IN ('S0001','S0002','S0003')"For this I created a parameterised command object in data environment and set the query as:Select * from StudMaster where StudID IN ( ? )
Then I called in vb code as:Dataenvironment1.command1 ("'S0001','S0002','S0003'")
Is there anything wrong in it? It is not working..Plz help me out, how can I make it run.
I am tring to bind a data to listbox with where combobox.selectedvalue. My code is below; I am using data entity in wpf project;
Class Window1
Dim db As New AdvanceEntities
Private Sub Window1_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded[code].....
Also I need to create a query with Join In statement. I need to get two table in one query, they have same values in USERID collumn.
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how can get the name of the table that = to the name of the combobox1 when i select it.
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I have developed an ASP page in Visual web developer that retrieves the data usingan AccessDataSource object. I have the following UPDATE Command:
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I am trying to create a LINQ query statement that retrieve intersecting data from 3 datatables (dt, dt1, dt2). My first attempt to do so with the following LINQ query statement was successful: [code] However in my design, I would need the LINQ query statement to be dynamically generated, because I want a user to be able to retrieve intersecting data entries from VARIABLE number of datatables. In this case, the first option is not as good as the "INTERSECT" query operator, with which I can just easily connect each SQL query statement with a "INTERSECT" operator. The problem is that my second attempt using the "intersect" operator fails, and after many trials and errors I still can't get it to work. [code]
View 5 RepliesI am trying to bind an Access database to a MSChart control in VB Net 2008. I have a test database populated with four fields SAMPLE-DateTime, Values-Number, MAX-Number and MIN-Number. I'd like to only display the rows that fall within a specific date range but I'm running into a problem when i try to execute the following command:
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I have been debugging my code for a while and looking at posts in other forums, but it seems to be that everyone has a different problem than mine and what works for them will not work for me.My dropdown list is supposed to filter a gridview by choosing all the Companies that are associated to a certain product. The solution I have found online is that most people did not have DataKeyNames set in their gridview. I do have this set, but not to CompanyID. It wouldn't make any sense. So I have no idea what I am supposed to do since this is the only answer I have found.
<asp:DropDownList ID="ddlCompany" runat="server" DataSourceID="dsCompanyFilter"
DataTextField="CompanyName" DataValueField="CompanyID" AppendDataBoundItems="true"
AutoPostBack="true">
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I have one scalar value function defined in sql database.It accespts 2 parameters and return an integer.Can anyone please help how to call UDF from vb.net using oledeb?
View 1 RepliesMust Declare Scalar Variable @ID?
View 11 RepliesThis seems so basic but I've been struggling to find a solution! I have a web page that take user data from aspx textboxes. Upon hitting a button, the click event submits the responses to a SQL table. Seems easy.I'm using VS10, dev express and VB code. I have established my datacontext class using LinqToSql...In a nutshell, the code is as follows...within the click eventNote that "database" was earlier defined as my datacontext sql connection, "Request" tablee
Dim vname As String = AspxTextbox1.Text
database.executecommand("INSERT INTO [Requests] (ContactName) Values (@vname)")
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im having this prob, when deleting a line from my gridview, this error shows out.Must declare the scalar variable "@productid".Well, i dont know whats wrong with the coding. As i have already declared the productid.
<table style="width:100%;">
<tr>
<td class="style24" colspan="2">
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
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I've done some research and I'm not sure what to look for or what my problem is.My error is: "Must declare the scalar variable '@client_id'"
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I am getting the following screen shot error when I am testing my code.
vb
Private Sub cmdLogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdLogin.Click
'get todays date and assign it to a variable
Dim TodaysDate As Date = Now
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At first I was using this as an extension method to update my detached entities...
Public Sub AttachUpdated(ByVal obj As ObjectContext, ByVal objectDetached As EntityObject)
If objectDetached.EntityState = EntityState.Detached Then
Dim original As Object = Nothing
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Everything has been working great until I had to update non-scalar properties. Correct me if I am wrong but that is because "ApplyCurrentValues" only supports scalars. To get around this I was just saving the FK_ID field instead of the entity object relation. Now I am faced with a many to many relationship so its not that simple. I would like to do something like this...
Dim Resource = RelatedResource.GetByID(item.Value)
Condition.RelatedResources.Add(Resource)
But when I call SaveChanges the added Resources aren't saved. I started to play around with self-tracking entities but it seems they cannot be serialized to ViewState and this is a requirement for me.how to either save my many to many relationships or serialize self-tracking entities?
I double check the query and it is still throwing the error..
sql = "INSERT INTO " & tbl & " (userName,userPassword,userAccessLevel, "
sql = sql & "userDateCreated,userFirstName,userMiddleName,userLastName, "
sql = sql & "lastUpdateDate,lastUpdateBy) "
sql = sql & "VALUES (@u,@p,@lvl,@dateC,@Fname,@MName,@LName,@lud,@lub)"
Dim p As SqlParameter() = New SqlParameter() _
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I'm trying to get a connection established for an OLEDB connection, but since I've never used it, I don't really know what I am doing wrong. I managed to get a connection in the web.config file, I think, but now I get the 'must declare scalar variable' error. I thought I declared it, but it. [code]
View 1 RepliesWe build a class (i.e. Server) and create a LOAD method that loads a dataset with all the details of that object.We need all that information sometimes... but what about when we only need one piece of data from that object (i.e. webserviceUrl).Should we build classes with a bunch of scalar methods that get back single pieces of data as opposed to only getting ALL the data and then only taking what we need?It's a waste to get all the data when we dont always need all of it but it also will take longer to write the extra methods..
View 2 RepliesI have been stuck for a long time on this simple but obtuse message "Must Declare the Scalar Variable"
I have a vb.net and SQL code that inserts data into a simple table. It works OK with sample data, but when I try to use a parameter (insertcommand.Parameters.Add("@ID", SqlDbType.Int, 3).Value = 50) it gives me the error. If I replace the @ID with just a number it works.
Eventually .Value = txtid.text if I can get the parameter to work.
Dim connection As New SqlConnection
Dim connectionString As String =
"Data Source=LAPTOP-PCSQLEXPRESS2008;Initial Catalog=golf;" &
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