SqlDataReader: Accessing Columns With The Same Name!
May 12, 2008
Hi there
I am using an SqlDataReader to read and write to my back end database and i have got it to work using the code: myDataReader["myFieldName"].ToString();
However, when i have two fields of the same name (e.g a "Surname" belonging to students in a table, and "Surname" belonging to teachers in a different table), I can't Pick up the two different fields even though i have given aliases.
I don't really want to access these fields using an integer as the index as this will make management in the future difficult.
as a side note, i have to use aliases as i access the teachers table a number of different times to specify who the tutors are and who teachers of all their different subjects are.
Hi,I use SqlDataReader to read one row from database and than set some properties to values retrieved like this:string myString = myReader.GetValue(0) // this sets myString to first value in a rowIf, however, I change order of columns returned by stored procedure myString would be set to wrong value. Is there a way to do something like this: string myString = myReader.GetValue["ColumnName"];
I'm creating a new Integration Services Project that copies data out of a SQL 7 server, transforms it, and places the data on a SQL 2005 (SP 2) Server. When defining a lookup transformation, if I specify an OLE DB Connection to my server running SQL 7 as the reference table, as soon as I click on the Colums tab, Visual Studio closes / crashes and dumps me to windows. I don't get an error message. If however I specify a connection to a server running SQL 8, or SQL 2005, no problems.
Is this supposed to happen?
My workstation is running Windows XP Pro SP2, Visual Studio 2005 Pro.
Microsoft SQL Server Integration Services Designer Version 9.00.1399.00
The server that doesn't work for a reference table is running Windows 2000 Server SP4 SQL 7.00.623
Hi.. Every time I want to read any record from data base I read it in dataset for example:SqlConnection con = new SqlConnection(@"Data Source=localhost ;Initial Catalog=university ;Integrated Security=True"); SqlCommand cmd = new SqlCommand("select [User_AuthorityID] from users where [UserID]='" + TextBox1.Text + "' and [UserPassword]='" + TextBox2.Text + "' ", con);SqlDataAdapter adp = new SqlDataAdapter(); adp.SelectCommand = cmd;DataSet ds = new DataSet(); adp.Fill(ds, "UserID");foreach (DataRow dr in ds.Tables["UserID"].Rows) { user_type = dr[0].ToString(); Session.Add("User_AuthorityID", user_type); ......... Is there easier way to read data from data base? How I can use SqlDataReader to do that? Thanks..
Hey All, I have come across a situation with two tables, they are dynamic and the user can add and edit values in the tables so I need to build a dynamic display control. It is all based around an FAQ system I have built. The user can create new FAQ categories (that is one table) then create a new FAQ Question & Answer (that is the second table). The tables are linked by the category id. So now I am trying to display the FAQ section like so. CATEGORY NAME QuestionAnswerQuestionAnswerCATEGORY NAME QuestionAnswerQuestionAnswerCATEGORY NAME QuestionAnswerQuestionAnswer So my idea was to run a loop within a loop. First loop the category name, then within the category name, loop a second time to grab all of the questions & answers within the category id captured from the first loops sql select statement, then proceed to loop the category name again and of course repeat the process until all loops are completed. However I am getting, and I kinda figured I would get an error about my SQLDataReader. Bellow is my code maybe some type of edit or different recommendation is needed. Any help will do, thanks!Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load '--- Database Connection ---Dim sConnStr As String = ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString Dim cnBKPost As New SqlConnection(sConnStr) '--- End DB Connection ---- '----- FAQ's ------- Dim sql As String = "SELECT category_id, category_name FROM faq_category ORDER BY category_name DESC"Dim cmd As New SqlCommand(sql, cnBKPost) cnBKPost.Open()Dim reader As SqlDataReader = cmd.ExecuteReader() Dim str As New StringBuilder() Dim catid As IntegerDo While reader.Read() '--- Category Titles ----catid = reader("category_id") str.Append("<h2>" & reader("category_name") & "</h2>") '--- End Category Title --- '--- Get FAQ's In Category --- Dim sqlcat As String = "SELECT faq_question, faq_answer FROM tbl_faq WHERE faq_category = '" & catid & "'"Dim cmdcat As New SqlCommand(sqlcat, cnBKPost) Dim readerfaq As SqlDataReader = cmdcat.ExecuteReader()Do While readerfaq.Read() str.Append("<p><font style='font-size:12pt;font-color:#daa520;>'" & reader("faq_question") & "</font><br />")str.Append(reader("faq_answer") & "</p>") str.Append("<br /><br /><br />") Loop readerfaq.Close() '--- End Get FAQ's in Category --- Loop reader.Close() cnBKPost.Close()Me.Literal1.Text = str.ToString() End Sub End Class
i'm using c# and SqlDataReader to simply retrieve data from one column of a database. problem is it's an integer i'm trying to retrieve, and so i'm trying to put it into an int variable, and i get the error "CS0029: Cannot implicitly convert type 'object' to 'int'" . i've looked for an answer for about an hour and every example for the SqlDataReader that i can find deals with strings only or the examples are too complex for me to understand.
there must be an easy way to retrieve this data and put it into an integer! help...
my line of code that creates the error:
int intGuestNum = dtrSelectTotalSessions["online_numSessions"];
Hi, from what I can find, there isn't a way to get the number of rows returned from a SQLDataReader command. Is this correct? If so, is there a way around this? My SQLDataReader command is as follows:Dim commandInd As New System.Data.OleDb.OleDbDataAdapter(strQueryCombined, connInd)Dim commandSQL As New SqlCommand("GetAssetList2", connStringSQL)Dim resultDS As New Data.DataSet()'// Fill the dataset with valuescommandInd.Fill(resultDS)'// Get the XML values of the dataset to send to SQL server and run a new queryDim strXML As String = resultDS.GetXml()Dim xmlFileList As SqlParameterDim strContainsClause As SqlParameter'// Create and execute the search against SQL ServerconnStringSQL.Open()commandSQL.CommandType = Data.CommandType.StoredProcedurecommandSQL.Parameters.Add("@xmlFileList", Data.SqlDbType.VarChar, 1000).Value = strXMLcommandSQL.Parameters.Add("@strContainsClause", Data.SqlDbType.VarChar, 1000).Value = strContainsConstructDim sqlReaderSource As SqlDataReader = commandSQL.ExecuteReader()results.DataSource = sqlReaderSourceresults.DataBind()connStringSQL.Close()And the stored procedure is such:DROP PROC dbo.GetAssetList2;GOCREATE PROC dbo.GetAssetList2(@xmlFileList varchar(1000),@strContainsClause varchar(1000))ASBEGINSET NOCOUNT ONDECLARE @intDocHandle intEXEC sp_xml_preparedocument @intDocHandle OUTPUT, @xmlFileListSELECT DISTINCTAssetsMaster.AssetMasterUID,SupportedFiles.AssetPath,FROM AssetsMaster, OPENXML (@intDocHandle, '/NewDataSet/Table',2) WITH (FILENAME varchar(256)) AS x,SupportedFilesWHEREAssetsMaster.AssetFileName = x.FILENAMEAND AssetsMaster.Extension = SupportedFiles.Extension UNIONSELECT DISTINCTAssetsMaster.AssetMasterUID,SupportedFiles.AssetPath,FROM AssetsMaster, OPENXML (@intDocHandle, '/NewDataSet/Table',2) WITH (FILENAME varchar(256)) AS x,SupportedFilesWHEREAssetsMaster.AssetFileName <> x.FILENAMEAND CONTAINS ((Description, Keywords), @strContainsClause)AND AssetsMaster.Extension = SupportedFiles.ExtensionORDER BY AssetsMaster.Downloads DESCEXEC sp_xml_removedocument @intDocHandle ENDGOHow can I access the number of rows returned by this stored procedure?Thanks,James
How do I tell when there is no more data to read in a SQLDataReader? For example, I have an open datareader that I pass into a function that MIGHT still have a valid row in it when it returns from the function. How do I tell? I can't do a read() because then that current record will go away. I need to be able to tell if there is a current record without doing another read. TIA,
Say I have this SQL query running into an SqlDataReader select TaskName, TaskDescription from tblTasks where TaskID = 5 There are two different ways to get the data out of the reader (maybe more) TaskName.Text = Reader.GetString(0);andTaskName.Text = Reader.GetString(Reader.GetOrdinal("TaskName")); My question is, is there a major difference in terms of efficiency between these two? The second one is definitely more robuts (in a situation where you are calling a stored procedure, and the stored procedure might change, etc) but the first one has fewer operations. Is the increase in robustness of the second one worth the potential performance hit, if any? Thank you, -Madrak
May I know what is the purpose of having SqlDataReader in Example A? I can see the same output when I tried out both. Should I use Example A or Example B? Currently, I'm using Example B since it is lesser code.Example A Dim objDR As SqlDataReader 'Create Data Reader
LoginConn.Open() strSQL = "SELECT CountryID, CountryName FROM Country ORDER BY CountryName " cmd = New SqlCommand(strSQL, LoginConn) objDR = cmd.ExecuteReader() 'Populate the DataReader ddlNationality.DataSource = objDR ddlNationality.DataBind() ddlNationality.SelectedValue = dvUserProfile.Item(0)("Nationality")LoginConn.Close() Example BLoginConn.Open() strSQL = "SELECT CountryID, CountryName FROM Country ORDER BY CountryName " cmd = New SqlCommand(strSQL, LoginConn) ddlNationality.DataSource = cmd.ExecuteReader() 'Populate the DataReader ddlNationality.DataBind() ddlNationality.SelectedValue = dvUserProfile.Item(0)("Nationality")LoginConn.Close()
Hello every one and happy new year... i have a problem with SqlDataReader used in asp.net application: I defined a public object of SqlDataReader and assigned it the resultset of a query, well, this happened ,lets say in page 1# but whan i want to use this datareader in another page it keeps telling my that the reader is closed so i can't abstract information from, regarding that i used it's methods such "Read()" and "NextResult()" but there is no use, what should i do, help me please !!!!!?
Hello im fairly new to ASP.Net and have a problem with an Intranet Page I am creating. In this part of the page I want to retrive a value from an SQL Table based on criteria and then store it as a variable to be used elsewhere on my page. I have tried using the SQL Data reader to retrive the value but somewhere in my code I am going wrong. Can anyone advise me on this please? See code below My Visual Studio debugger has point out that there is a problem with my r = cmd.ExecuteReader() line Oh and the connection to my SQL database is opened further up the page from this code. Dim strSQL As String = "SELECT top 1 OrderID FROM tblStationeryOrder WHERE ORDERMADEBY = '" & lstUsers.SelectedValue & "' ORDER BY OrderID DESC"Dim cmd As New System.Data.SqlClient.SqlCommand cmd.CommandText = strSQLDim r As System.Data.SqlClient.SqlDataReader r = cmd.ExecuteReader()Do While r.Read() Dim OrderID As Integer = r!OrderID Exit Do
I found this tutorial at C# Station called "Reading Data with the SqlDataReader". In my code behind file I followed what I think the tutorial was telling me to do but I keep getting a syntax error near '='
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: Line 1: Incorrect syntax near '='. (Line 45: rdr = cmd.ExecuteReader();) Heres my code:
this is my code: and their is an error ,,really dunno where and why coz it seems logical to me :)Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click If RadioButton1.Checked = True Then
Dim admin As Stringadmin = "SELECT * from ADMINISTRATOR where UserName='" & TextBox1.Text & "' and UserPassword='" & TextBox2.Text & "'"
Dim sConnect As String = "Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|Database.mdf;Integrated Security=True;User Instance=True"Dim cnt As New SqlConnection cnt.ConnectionString = sConnect cnt.Open()Dim com As New SqlCommand com.Connection = cnt com.CommandText = adminerror!!>>>>Dim rd As SqlDataReader rd = com.ExecuteReader If rd.Read ThenSession("admn") = rd("UserName")Session("id") = rd("UserID") rd.Close() cnt.Close()Response.Redirect("~/adminpage.aspx") ElseSession("admn") = 0 Label3.Visible = True rd.Close() cnt.Close() End If Else Dim instrct As Stringinstrct = "SELECT * from instructor where name='" & TextBox1.Text & "' and passs='" & TextBox2.Text & "'"
Dim sConnect As String = "Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|Database.mdf;Integrated Security=True;User Instance=True"Dim con As New SqlConnection con.ConnectionString = sConnect con.Open()Dim com As New SqlCommand com.Connection = con com.CommandText = instrctDim r As SqlDataReader r = com.ExecuteReader If r.Read ThenSession("inst") = r("inst_name") r.Close() con.Close()Response.Redirect("~/instructorpage.aspx?id=" & Session("inst")) ElseSession("inst") = 0 Label3.Visible = True r.Close() con.Close() End If End If End Sub ----------------- this is the error line: The data types text and varchar are incompatible in the equal to operator. 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: The data types text and varchar are incompatible in the equal to operator.... so,,,any suggestions?
I have an sp, which has 2 select statements, so iam using a sqldatareader and binding the data to a dropdown. the first binding is fine, but when i say dataReader.NextResult(), It is null.It says the reader is closed. Can any one tell a work around for this.
error message is, Invalid attempt to call Read when reader is closed. 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 call Read when reader is closed.Source Error:
Line 77: if (sdr != null) Line 78: { Line 79: while (sdr.Read()) Line 80: { Line 81: ue.UserId = sdr["lecture_usr_id"].ToString();Source File: C:Users aphyrDocumentsVisual Studio 2008ProjectslectureBusinessLogicUserManager.cs Line: 77 I can't understand!!! I try to debuging!!! but, I don't know. please help me!
suppose I have a data reader which is returned by excuting a command "SELECT [xxx], [yyy], FROM [zzz]" , then I reads the data as normal. while I am reading , there is another thread that excute an insert command to that table , does this insertion effect the order of data that I am reading?
I have an SP that returns a result set that contains a tinyint. My problem is that, when I try and access this value using GetInt16 (or 32), I get an error saying that "Specified cast is not valid". TinyInt is 1 byte, or 8 bits. GetInt16 'Gets the value of the specified column as a 16-bit unsigned integer'. I am assuming that this is the root cause of my problem. But, there doesn't seem to be a GetInt8 ?! Any ideas? Thanks, Martin
hi..i am kind of new to asp.net n having trouble with the SqlException error message.. n this code works as 1st page pass the id to second page and the second page took the id to execute the query..i dun know the wer the error occurs..can give a help..Thanks. private void Page_Load(object sender, System.EventArgs e) {
SqlConnection connection = null; SqlCommand command = null; string sqlConnection = null; string sql = null; string ab = null; sqlConnection = ConfigurationSettings.AppSettings["MSQLConnectionString"]; connection = new SqlConnection(sqlConnection); if (!Page.IsPostBack) { try { if (Request.QueryString["categoryID"] == null) { } else { ab= Request.QueryString["categoryID"].ToString(); //getting the id from page that pass this values
sql = "Select groupname, categoryid, description from groups where groups.categoryid=?"; // can this query execute? command = new SqlCommand(sql, connection); connection.Open(); command.Parameters.Add(new SqlParameter("categoryid", ab)); reader = command.ExecuteReader(); // error on here "SqlException" while (reader.Read()) { group.InnerText = reader["groupname"].ToString(); desc.InnerText = reader["description"].ToString();
Case: Exporting Report to PDF/Printing/TIFF Report: Contains 1 table with 19 Columns. 1 column is static, the other 18 are visible at the users descretion. Report when printed/exported to pdf spans 2 pages naturally, 16 on the first page, 3 on the second, and the column widths have been adjusted to provide a perfect page span .
User A elects to hide two of the columns, and show the rest. The report complies and the viewable version is perfect, the excel export is perfect.. the PDF export on the first page causes every fith column, starting with the last column that was hidden to be expanded to take up additional width. On the spanned page, it renders the first column on that page correctly, then there is a white space gap equal to the width of the hidden columns and then the rest of the cells show with the last column expanded to take up the same width that the original 2 columns were going to take up, plus its width.
We have tried several different settings to see if it helps this issue or makes it worse. So far cangrow/canshrink/keep together have made no impact. It is not possible to increase the page size due to limited page size selection availablility for the client. There are far too many combinations of what the user can elect to show or hide to put together different tables to show and hide on the same report to remove this effect.
Any help or suggestion on this issue would be appreciated
My query is as follows:Dim CurrentDate As DateCurrentDate = "09/02/2007" MyCommand = New SqlCommand("SELECT RegisterID FROM Registers WHERE RegisterDate = @RegisterDate AND IsMorningRegister = 1", MyConn)MyCommand.Parameters.Add("@RegisterDate", Data.SqlDbType.DateTime)MyCommand.Parameters("@RegisterDate").Value = CurrentDate My DB table is called RegisterDate and is of type DateTime. The record that should be matched is: Register ID: 13 RegisterDate: 09/02/2007 09:00:00IsMorningRegister: TrueIsAfternoonRegister: False But no records are returned. Any idea why?
I am trying to access data using this code: SqlCommand myCommand = new SqlCommand("myStoredProcedure", myConnection); myCommand.CommandType = CommandType.StoredProcedure; myCommand.Parameters.Add(new SqlParameter("@myID", SqlDbType.Int)); myCommand.Parameters["@myID"].Value = myIDValue; myConnection.Open(); myDataReader = myCommand.ExecuteReader(); myTextBox.Text = myDataReader["myColumn"].ToString(); myDataReader.Close(); myConnection.Close(); I get "data reader has no data" error. A problem with the parameter? The stored procedure returns a row when executed from the database explorer. I have used datasets and table adapters up to now as in the data access tutorial on this site Any Ideas?
Hello, im using sqldatareader to read my data and whenever time i loop through the reader it starts from second row why is that? here is my code:while (reader.Read()){hinfo.Name = reader["_name"].ToString();hi.Add(hinfo);} i look at the database and i have two rows but its reading only the second row, skiping the first row
I am getting a random exception coming out of ADO.NET's SqlDataReader that I can't seem to track down for the life of me. I have put SQL Server and IIS under heavy load, with neither giving me the exceptions except occasionally (they come when there is no load as well). Web Site is built in VS2005 using .NET 2.0. Basically, I have a web page that caches a few tables from a SQL database (about 10 tables are loaded into cache from this page) and the error can come from any of the tables while they are being read from the database randomly. I had assumed it was possible that a timeout was occuring while reading the data but from what the brief results google shows, there would be a different exception thrown it a timeout had occured. Here is the exception that is showing up: System.NullReferenceException: Object reference not set to an instance of an object. at System.Data.SqlClient.SqlDataReader.ReadColumnHeader(Int32 i) at System.Data.SqlClient.SqlDataReader.ReadColumn(Int32 i, Boolean setTimeout) at System.Data.SqlClient.SqlDataReader.GetValueInternal(Int32 i) at System.Data.SqlClient.SqlDataReader.GetValue(Int32 i) at Library.Data.DataProxy.ExecuteStoredProcedure(ArrayList& returnValues, TypeFactory factory) I got the following exception once from the same section of code as well: System.InvalidOperationException: Invalid attempt to FieldCount when reader is closed. at System.Data.SqlClient.SqlDataReader.get_FieldCount() at Library.Data.DataProxy.ExecuteStoredProcedure(ArrayList& returnValues, TypeFactory factory) The code generating these errors is on line 29 below: 1 /// <summary>2 /// Executes a stored procedure that returns values3 /// </summary>4 /// <param name="returnValues">An arraylist of Types</param>5 /// <param name="factory">The Type specific factory</param>6 /// <returns>True if successful, false otherwise</returns>7 public bool ExecuteStoredProcedure(out ArrayList returnValues, TypeFactory factory)8 {9 bool bResult = true;10 SqlDataReader reader = null;11 12 returnValues = new ArrayList();13 MenseType nextType = null;14 15 try16 {17 // Open database connection18 OpenConnection();19 20 // execute SP21 reader = m_sqlCommand.ExecuteReader();22 23 while(reader.Read())24 {25 nextType = factory.CreateInstance();26 27 for(int i = 0; i < reader.FieldCount; i++)28 {29 object val = reader.GetValue(i);30 31 if(DBNull.Value == val)32 val = null;33 34 nextType.SetValue(reader.GetName(i), val);35 }36 37 returnValues.Add(nextType);38 39 } // while40 41 } // @ try42 catch(Exception ex)43 {44 returnValues = null;45 m_LastError = ex.ToString();46 bResult = false;47 48 #if(DEBUG)49 Library.IO.Logging.AddSQLMessage(ex);50 #endif51 52 } // @ catch53 finally54 {55 // close the reader if nessessary56 if (null != reader)57 reader.Close();58 59 // close db connection60 CloseConnection();61 62 } // @ finally63 64 return bResult;65 66 } // ExecuteStoredProcedure() Any input would be greatly appreciated.
I have an SqlDataReader which loops through records returned from an SP, within that loop I would like to initiate another SP, but for some darn reason the following code won't work: // create SqlConnection object string ConnectionString = ConfigurationManager.ConnectionStrings["aiv3cs"].ConnectionString; SqlConnection myConnection = new SqlConnection(ConnectionString);
try { // Create a new XmlTextWriter instance XmlTextWriter writer = new XmlTextWriter(Server.MapPath("products.sitemap"), Encoding.UTF8);
// end the xml document and close writer.WriteEndElement(); writer.WriteEndDocument(); writer.Close(); }
finally { myConnection.Close(); }I've gotten the following two errors:There is already an open DataReader associated with this Command which must be closed first.And a build error:Error29The type 'System.Data.SqlClient.SqlDataReader' has no constructors defined Any suggestions would be most appreciated.
Hi, I am pretty new to harcore ASP.NET and .NET in general but I know the basics of the language and stuff like that. Basically I used to be a hardcore object pascal Delphi developer doing Windows Applications but have now moved to .NET world. The reason I posted this question here is I couldn't find any other specific place to ask so here it goes. To get me started with good programming source and practices I downloaded the ASP.NET TimeTracker Starter Kit and after some modificaion in connection string (using SQL 2005 Developer edition not the Express one) I have managed to make it work. Things done in there are pretty interesting way by using a delegate to retrieve data and present it using databound controls. As much simple as it sounds I am more of a fan of not using too many databound controls except in dropdown box, list box and stuff like that. So basically I need to develop DataAccessLayer (DAL) in such a way that it's useful for both Windows and Web application. So with my research I found that I should be using DataSets in the DAL because they are serializable and thatz what Web Applications & Services love over using SqlDataReader. Other advantage of using DataSet is to use ForEach syntex over While Loop in SqlDataReaders. So below is some code I extracted from the TimeTracker Starter Kit to get me started. I also noticed that the return result is a list array of certain object, in this case Category. So does it mean that it can be used in frontend using ForEach syntex? How can I convert the code below to use DataSets over SqlDataReader? Private Delegate Sub TGenerateListFromReader(Of T)(ByVal returnData As SqlDataReader, ByRef tempList As List(Of T))
Public Overrides Function GetAllCategories() As List(Of Category) Dim sqlCmd As SqlCommand = New SqlCommand() SetCommandType(sqlCmd, CommandType.StoredProcedure, SP_CATEGORY_GETALLCATEGORIES)
Dim categoryList As New List(Of Category)() TExecuteReaderCmd(Of Category)(sqlCmd, AddressOf TGenerateCategoryListFromReader(Of Category), categoryList)
Return categoryList End Function
Public Overrides Function GetCategoryByCategoryId(ByVal Id As Integer) As Category If Id <= DefaultValues.GetCategoryIdMinValue() Then Throw New ArgumentOutOfRangeException("Id") End If
Dim sqlCmd As SqlCommand = New SqlCommand() AddParamToSQLCmd(sqlCmd, "@CategoryId", SqlDbType.Int, 0, ParameterDirection.Input, Id) SetCommandType(sqlCmd, CommandType.StoredProcedure, SP_CATEGORY_GETCATEGORYBYID)
Dim categoryList As New List(Of Category)() TExecuteReaderCmd(Of Category)(sqlCmd, AddressOf TGenerateCategoryListFromReader(Of Category), categoryList)
If categoryList.Count > 0 Then Return categoryList(0) Else Return Nothing End If End Function
Private Sub TGenerateCategoryListFromReader(Of T)(ByVal returnData As SqlDataReader, ByRef categoryList As List(Of Category)) Do While returnData.Read()
Dim actualDuration As Decimal = 0 If Not returnData("CategoryActualDuration") Is DBNull.Value Then actualDuration = Convert.ToDecimal(returnData("CategoryActualDuration")) End If
Dim category As Category = New Category(CStr(returnData("CategoryAbbreviation")), actualDuration, _ CInt(returnData("CategoryId")), CDec(returnData("CategoryEstimateDuration")), CStr(returnData("CategoryName")), _ CInt(returnData("ProjectId"))) categoryList.Add(category) Loop End Sub Hope this makes sense. Sorry if I have posted this in a wrong section..! Cheers,Nirav
I'm having some trouble reading data from a query. This has to do with a previous posting here:view post 504339
I have corrected that problem but I now only get the response "wrong password" even though the right password is entered. Here is the new code for the click subrouthine. You will notice two different scenarios with one commented out. Both do not work. I created label1 to display the password and it is show correctly. What am I doing wrong?
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click Dim test As String SqlConnection1.Open() SqlCommand1.Parameters.Item("@email").Value = txtUsername.Text Dim dr As SqlDataReader = SqlCommand1.ExecuteReader If dr.Read() Then test = CStr(dr("pass")) Label1.Text = test 'If dr("pass").ToString = txtPassword.Text Then 'lblMessage.Text = "login successful" 'Else ' lblMessage.Text = "Wrong password" 'End If If String.Compare("test", "txtPassword.text") = 0 Then lblMessage.Text = "login successful" Else lblMessage.Text = "Wrong Password" End If Else lblMessage.Text = "Please register" End If dr.Close() SqlConnection1.Close() End Sub
In my database I have this code: Do While sqlDataReader.Read() lblTitle.InnerText = sqlDataReader.GetString(2) Loop
And this will get my sql's 3rd column ( its #2 because its 0-indexed ), but I am throwing this error when I try to print this sqlDataReader.GetString(2) if this particular value is a int. How do I cast it to a String.
I have already done these two things: sqlDataReader.GetString(2).ToString() & CStr(sqlDataReader.GetString(2))
HiI try to retriveing data from database using following code (code-behind page). then put data into form fields. It tells me SqlDataReader is not defined. What does this mean? I am using Visual Studio.net and new to it. Please help. thnaks.---------------------------------------------------------------------------------------Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim myReader As SqlDataReader = myCommand.ExecuteReader() If myReader.HasRows Then Do While myReader.Read() txtfname.Text = myReader("fname") txtlname.Text = myReader("lname") Loop Else Console.WriteLine("No rows returned.") End If myReader.Close() End Sub
Hi all,Is there a data transfer difference between returning a datareader that only has one row or using output parameters? For instance, I have a login page that shows the last login, member since, display level, number of file views, etc. Currently I am returning a datareader that reads one row and assigns this data to labels. But would it be quicker to use OUTPUT parameters instead of using a dataread and just get the values from the command object?ThanksJosh
I have a DAL that I'm trying to implement - the issue is that I want to call a reader from the DAL, but I'm not sure how to close it. I got best practices from MSDN (located here: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemdatasqlclientsqldatareaderclasstopic.asp ) regarding the SqlDataReader, but can't seem to figure out how to close when using DAL. Here is sample code in C#: NOTE: Everything WORKS just fine, however in the DAL for GetRoutes, I can't seem to figure out how to close the reader (see comments in function): mydatapage.aspx...//Populating some Drop Down List:private void ddlRoutes_SelectedIndexChanged(object sender, System.EventArgs e) { SqlDataReader dr = DAL.GetRoutes(ddlRoutes.SelectedValue.ToString()); while (dr.Read()) { . . . }} DataAccessLayer.cs...public static SqlDataReader GetRoutes(string sIdx){ cnn = new SqlConnection(ConnectionString); cnn.Open(); SqlCommand cmd = new SqlCommand(); SqlParameter par = new SqlParameter(); cmd.Connection=cnn; cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "sp_GetRoutes"; return cmd.ExecuteReader(); //Everything works above, however I would think that something //like this SHOULD work, but doesn't: // // SqlDataReader dr; // dr = cmd.ExecuteReader() // return dr; // cnn.close(); }
