ADO.NET :: Linq2Sql Error: "Invalid Attempt To Call Read When Reader Is Closed"
Aug 24, 2010
I've read up on this error from other posts and on other sites, but haven't found a solid resolution to the issue yet. My setup is as follows:
I have a RepositoryBase class that fields certain db calls that all repositories need to perform. In one such call, "GetSecurityGroup", it works most of the time, but will seemingly at random throw an exception with the error "Invalid attempt to call Read when reader is closed." All other Repository classes inherit from this one, and they all use the same DataContext object, which I understand isn't thread safe. Since there could be multiple calls to the DataContext object on the same page, perhaps one is using the DataContext when the next tries to do so. I'm not sure. What can I do to ensure this doesn't happen?
I have a function which allows me to quickly load SQL results into an SQLDataReader.
This is a very effective way for me to do this as it can be used for inserts, updates and selects very easily throughout my code.
However, I have noticed some potential memory issues with my site while using this (I keep having to do iisresets when working locally because all the pools are used up) so I am trying to use "Using" rather than "Dim" in an effort to ensure that the connection is always disposed.
I call the function in the following way:
Dim RS As SqlDataReader = SQL.Exec("sp_MyStoredProcedure " & ID) If RS.Read Then Return RS("Column_Name") End If RS.Close()
[Code].....
I now get the error "Invalid attempt to call Read when reader is closed" when calling the function on the line "If RS.Read Then".
Environment is : vwd2008, asp.net 3.5, linq to sql object model, formview, stored procedure used for query.On going problem... I have a simplified page with a webform content area from a master page. The content area contains a FormView connected to an object data source thru the design view tag. The O/R designer has the Lease Table and the stored procedure in the method area.
The stored procedure selects all records from a single table. I an using the DatabaseDataContext and selecting stored procedure name which has "return SingleResult".. There is no code written; the design view was used to create everything. The stored procedure executes in VWD 2008 express tab and shows desired records. I would like to use the O/R and Linq to SQL, and objectdatasource BUT.
I am creating a C# web application where I am attempting to extract data from my SQL Server and return the data in a single data stream into the properties of my object instance. Here is the code from my Presentation Layer where I am calling the Load method of my BLL:
[Code]....
Here is the code for the method in my BLL:
[Code]....
Here is the fillObject method from the BLL as well:
[Code]....
Here is the code from my DAL:
[Code]....
In the end I get an "Object reference not set to an instance of an object" error on the next line of code in my Presentation Layer. However, when I step through the code I notice the myDataReader in the BLL does not get populated and the step through actually errors out during the fillObject method at the line "myObject.string1 =" with the error stated in the title. I am not sure why the myDataReader in the BLL is closed and why I this does not work. At my work we have this same code logic only in VB.Net and it works perfectly. have any insight as to why this does not work in C# and how can I correct this?
so i have a content page that load some content into repeater one of the repeater items is UserControl, when the page is load for the first time everything is perfect, but if i try to do postback and reload the repeater i get this error: Code:
Exception Details: MySql.Data.MySqlClient.MySqlException: Invalid attempt to Read when reader is closed.
this error is raised in the repeater databind event.
I am getting the following error when i am trying to assign values to controls on form via datareader, i know i got one row. but this particular field has no data in it.
I do have lot of other forms where i use the same style
getting this error: invalid attempt to read when no data is present
on this line: If gDatareader("CutoffDate") Is DBNull.Value Then
I have several methods where I return a SqlDataReader to populate Gridviews, Listview, etc. I get random "Timeout expired" errors regarding connection pooling, so I decided to add using{} to my methods. The lack of using is a carry over from my more beginner days.Below I included the before and after code. The after code always gives me the "Invalid attempt to call FieldCount when reader is closed" error. I have tried various combination of using{}, but ALL result in the same error.What am I doing wrong? Also, from the code below what is the best way to structure this code to ensure no connection leakage?Before:
Server Error in '/AviaBellaVidaChecklist' Application.
Invalid attempt to read when no data is present. 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.InvalidOperationException: Invalid attempt to read when no data is present.
I want to creat dynamic <asp:table ID=""...> and I want to have a totalAmount column by reading the first cell from my datareader and put it into total, this column must show the cumulative numbers....
Invalid attempt to read when no data is present.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.InvalidOperationException: Invalid attempt to read when no data is present.Source Error:
I want to get the total data of my table and store into one variableThis is my code...but it gives me error like 'Invalid attempt to read when no data is present.'
I have some code in my vb.net code behind that queries a database, and if there is data, outputs it from the codebehind to a datalist on my asp.net page. In addition to sending the data to the datalist on the page, I need to take the value from "mbillaty" that is returned from the sql query, and have that value be the selected value for a drop down box also on the page. I can get either the datalist to fill, or the selected value for the dropdown box to be selected depending upon which bit of code I place before the other (ARGH), but I can't get them to both work together on the page. What am I doing wrong?
Recently, I added a button, a textbox and a jquery code. On click of button the textbox value was been captured in the dropdown. All my code is working fine. But, when I fill the other data and submit the form, It gives me the below error.
however I can only create the last image instead of 5 images.
- imageID - cat5
I assign each image unique ID.
If reader2.HasRows Then While reader2.Read Dim img1 = Convert.ToString(reader2("imgtag1")) Dim img2 = Convert.ToString(reader2("imgtag2")) Dim img3 = Convert.ToString(reader2("imgtag3")) Dim img4 = Convert.ToString(reader2("imgtag4")) Dim img5 = Convert.ToString(reader2("imgtag5")) Dim blogimg = Convert.ToString(reader2("ImageID")) Dim a As New HyperLink a.Attributes.Add("onclick", "return hs.expand(this)") a.Attributes.Add("href", "../../blog/images/" + blogimg) Dim img As Image = New Image img.ImageUrl = "~/blog/images/" + blogimg img.Width = 200 If img1 = "1" Then Dim blogimg1 As HtmlTableCell = CType(FindControl("blogimg1"), HtmlTableCell) img.ID = blogimg + "1" a.Controls.Add(img) blogimg1.Controls.Add(a) ListBox1.Items.Add(blogimg + "1") End If If img2 = "1" Then Dim blogimg2 As HtmlTableCell = CType(FindControl("blogimg2"), HtmlTableCell) img.ID = blogimg + "2" a.Controls.Add(img) blogimg2.Controls.Add(a) ListBox1.Items.Add(blogimg + "2") End If If img3 = "1" Then Dim blogimg3 As HtmlTableCell = CType(FindControl("blogimg3"), HtmlTableCell) img.ID = blogimg + "3" a.Controls.Add(img) blogimg3.Controls.Add(a) ListBox1.Items.Add(blogimg + "3") End If If img4 = "1" Then Dim blogimg4 As HtmlTableCell = CType(FindControl("blogimg4"), HtmlTableCell) img.ID = blogimg + "4" a.Controls.Add(img) blogimg4.Controls.Add(a) ListBox1.Items.Add(blogimg + "4") End If If img5 = "1" Then Dim blogimg5 As HtmlTableCell = CType(FindControl("blogimg5"), HtmlTableCell) img.ID = blogimg + "5" a.Controls.Add(img) blogimg5.Controls.Add(a) ListBox1.Items.Add(blogimg + "5") End If End While
I have been able to successfully read a row of data from an SQL table using two column parameters. Now I would like to update this row with new information. Is this possible since the reader does not specify which row was read with the 'reader.Read();' command?
I used the barcode example to my application and it generated barcode perfectly now I want to know that can this barcode image is readable by a barcode reader device ?
If Yes then how and if no then why and how to do ?
I'm receiving the following error occasionally when calling web service using a .NET 4.0 web application."The underlying connection was closed: An unexpected error occurred on a send."All of the articles I've read regarding this issue are for the Framework 1.1.Is there any solution to this issue for using .NET framework 4.0?
I am consuming a third party web service wsdl using my .net aps.net page. And I am getting following error message. Cannt get to resolve it. Its working on my machine but not in my development machine. I have installed the certificate also in certificates on that machine.
Error --> The underlying connection was closed: An unexpected error occurred on a send.
I'm currently working on an ASP.NET app that I inherited. There are a variety of file operations it has to perform and I'm getting and Access denied error when I attempt to create a directory.I've confirmed that the correct account is being impersonated and authenticated by checking WindowsIdentity.GetCurrent I've also confirmed that the account has full control for the parent folder of the directory I'm trying to create.The only think I can think of is that there might be an issue using a domain account rather than a local account. I'm not really 100% solid on how permissions work in this situation.Any ideas on why the account wouldn't have access? Is there any other code I could try to get more details about what is going on?
