Using DataReader In .NET

Jul 6, 2011

I got the error message There is an open data reader associated with this command which needs to be closed first by using the following code:

myCommand = New SqlCommand("SELECT BookCode FROM tblBook",myConnection)
myReader = myCommand.ExceuteReader
While myReader.Read

[Code]...

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VS 2010 : Create Multi-dimensional Array From Datareader From Datareader?

Feb 20, 2012

I have an SQL statement like:

SELECT FNAME, LNAME, CITY from EMPLOYEE

How do I create a multi-dimensional array from a datareader which should store values like:

John, Doe, LA
Mike, Johnson, PASADENA
Freddy, Kruger, Long Beach

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Datareader - Error - "there Is A Datareader Associate With This Connection That Need To Be Closed"

Aug 17, 2009

I have a problem with my project. here is the problem:

My code for login is as follows:

dim conn as SqlConnection = New SqlConnection("Data Source.................)
dim cmd as SqlCommand = New SqlCommand("Loguser",conn)
cmd.CammandType = CommandType.StoredProcedure

[CODE]...

Now the error i get is that "there is a datareader associate with this connection that need to be closed"

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.net - Datareader In VB And SQL?

Jun 22, 2010

i am working on a search feature for a program i am working on and i found a tutorial online that provides some insight but the actual code, after being modified to fit my aplication, does not work. i get two different errors as of right now, one that tells me "the value of type 'System.data.sqlclient.sqldatareader' cannot be converted to '1-dimensional array of system.data.sqlclient.sqldatareader" and the other that says"argument not specified for parameter 'array' of 'Public shared function... anyway i am kinda new to this and here is what i have so far. any advice?

Private Sub SearchOKButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SearchOKButton.Click

[Code]...

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.net - Going Through A DataReader Twice

Mar 30, 2011

I have the following code which does what it's supposed to do:

objSQLCommand = New SqlCommand("select * from table1", objSQLConnection)

objSQLCommand.Connection.Open()
objSQLDataReader = objSQLCommand.ExecuteReader()
While objSQLDataReader.Read()

[Code]....

But I need to loop through the objSQLDataReader 1 more time. How would I do that?

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Add A Value Manually To DataReader ?

Jun 10, 2011

I am copying sample.csv file's content into the new.csv file. But I need to add additional column in new.csv file which holds the default value as "Yes" for each row that exists in old file. Here is the code I have written.

Dim ioFile As New System.IO.StreamReader("C:sample.csv")
Dim ioLine As String
Dim ioLines As String[code].....

The first four columns ID,Name,Number,Amount are present in sample.csv.I am adding additional column Copied which should be "Yes" for each row.

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How To Loop A DataReader

Mar 18, 2009

If my Select statement finds data that matches the criteria, how do I get myReader (DataReader) to read each record when there are more then one record found?

Dim myReader As MySql.Data.MySqlClient.MySqlDataReader
myReader = myCommand.ExecuteReader()
If myReader.Read() Then

[code]....

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Only The First Record To Come In Datareader?

Sep 21, 2009

I am trying to tag of some words.There are 5 tag word in my database. but only the first record is coming.i want to

my codes
Public Function tags(ByVal ID As Integer) As String

[code].....

my html code in gridview <%#tags(Container.DataItem("ID"))%>

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Sql - Use Datareader While Getting A Value To The Textbox?

Apr 26, 2011

Hey Friend i am using a form with a *combobox*in which the items i have taken from the
sqldatabase named as balance and that sqldatabase have two columns one is customername and the
another is obbalance now .

In the form i had binded all the customer names from the table and now i have a textbox i want to do is
when the user selects the combobox.selected item any one customer name i need to display the obbalance of the selected customer in tat textbox

[Code]...

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Two DataReader In One TreeView ?

Dec 12, 2009

two DataReader in one TreeView ?


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VS 2008 Using A DataReader

Jan 27, 2010

I am working on a project which requires me to connect to a MySQL database. From there I query the database and need to do work on the returned values.

I can query the database just fine. However, now I need to do work on the results. The two columns returned are user_name and user_password. The rows are the user accounts. I would like to take my query results and put each column into its own arrary().

[code..]

Instead of writing the results to the console, I would like to write each column to an individual array. Is there an easier way to accomplish this task? Or, what is the code I must place within the loop to do this.

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.net - Fill DataTable From DataReader Row By Row

Aug 25, 2010

i want to fill a Datatable with a Datareader row by row but get an exception because the reader's columns have a different order than the Datatable's columns.

Why and how does a Datatable loads itself with a Datareader correctly, even so it has a column collection with different order?

I need to calculate values for every row so i dont want to load the Datatable completely but row for row. It has 25 columns so i dont want to set it all manually.

There must be a chance to load/fill/add a new row from a datareader without having the same column order(reader.GetSchemaTable?).

Following is what i have but what doesnt work:

Using reader As System.Data.SqlClient.SqlDataReader = command.ExecuteReader
'next line works(configInfo.DataSource is a Datatable)but is inappropriate
configInfo.DataSource.Load(reader)

[Code].....

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.net Datareader Already Open Error When Not Used Before

Jun 22, 2011

I have this sub as part of my login / logout system. When this sub is called to login users it works perfectly, but on logout it throws an error that doesn't make any sense to me.

[Code]...

This sets a nonsense email address so that when validate_session searches for a valid email/session combo in the db it trips the destruction of the sensitive session data.

The question boils down to this: Why is the error being thrown when the logout sub calls validate_session?

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Any Way To Reset Or Clear DataReader?

Mar 6, 2012

Is there an easy way to reset or clear a DataReader so it can be read through more than one time? I found a Close method but not an open method.

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Big Performance With Oracle DataReader In .Net

Nov 10, 2010

I have a few Oracle procedures that generate/return a large amount of data that I need to write out to a file.I'm currently trying to accomplish with a data-reader. It seems to be working, I've successfully generated a 479mb file without any trouble.It took less than 4 minutes from the time I retrieved the dataReader to complete the file.But the dataReader I get for a particular procedure is crawling.It's unbelievably slow.I modified my code to try and get a better idea of what is going on[code]I'm writing a PL/SQL block that will open that cursor to see if the performance issue exists when I remove the .Net code..

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Check Whether DataReader Has Data Or Not?

Nov 28, 2009

Again I have problem with checking whether DataReader object has data or not?

Dim cmd as SqlCommand
Dim drd as SqlDataReader
cmd = New SqlCommand ("SELECT * FROM Stock", conx)
drd = cmd.ExecuteReader()

[Code]...

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Compare A Textfield With The Value Of A Datareader?

Aug 1, 2011

This may perhaps be a stupid question but I just can't get it to work.

I have an if clause where I compare a textfield with the value of a datareader.

It looks a little like this if me.txtfield1.text <> reader("field1") OR me.txtfield2.text <> reader("field2") ETC... I do this for a lot of field.

But now I want to check if field2.text is string.empty and if it is I want to skip the comparison for that field.

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Compare Date In .net Using Datareader?

Aug 8, 2011

i want to compare two data values in my database.These two dates belong to two different columns.What i want to compare is if the date of one column greater by 6 months from the date of other column then it should give error.I want to pass this query to database and check,and later on depending on the result want to insert my other functionality?

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DataReader - No Data Found In Row

Jun 25, 2009

I have a form in where I work with some data readers. One of my readers only gets the information from the first row. When ever I try to get something from the second row onwards I get an error saying that "no data found in row". I am using "ExecuteReader" not "ExecuteScalar". I cannot understand why I get this behaviour. Here is the The reader that gets me this error is reader2.

Dim reader As OleDbDataReader
Dim reader1 As OleDbDataReader
Dim sql5 As String
Dim SQL As String
sql5 = "SELECT * FROM Services WHERE ServiceID = " & Me.ServiceIDTextBox1.Text & ""
[Code].....

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Datareader And Empty Records?

Jan 26, 2009

I have a sql query that sometimes returns nothing...not null, just nothing.

This is causing my datareader to error out.

Is there a function, like isDbNull, but is for empty recordsets?

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Datareader Reading From CSV File?

Oct 21, 2011

I try to create a funtion to return a datareader from CSV file as below but got a error said that

ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified(at cn.open())

Public Shared Function GetCSVAsDataReader(ByVal csvPath As String) As Odbc.OdbcDataReader
Dim fi As New FileInfo(csvPath)

[Code]....

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Datareader To Array List?

Mar 21, 2012

I want to load all of the LOCATIONS in the Location table to a Combobox and then for any found locations (in another table) to be deleted from that combobox. Im using a Array list, but can't get the Data reader to write to the Array list.

Dim SQL As String = ""
Dim Reader As OleDbDataReader
Dim i As Integer = 0
Dim LocationArray As ArrayList = Nothing

[Code]...

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DB/Reporting :: Datareader Has No Constructors?

Jul 7, 2008

im converting my classic vb class into vb.net class and im having some problems with my object.Query function

here is my obj.Query Function

Code:
Public Function Query(ByVal sqlStatement As String, Optional ByRef e As String = "") As SqlDataReader
Try

[Code].....

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Error In DataReader Is Not Closed

Sep 30, 2010

There is already an open DataReader associated with this Connection which must be closed first.

the error fails when it trying to read this [code]...

Is there is a connection between the Datareader and in initializing the transaction?

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ExecuteNonQuery Within The Loop Of A Datareader?

Nov 19, 2011

can i do ( ExecuteNonQuery within the loop of a datareader ) in vb.net please help me with example

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Export To Excel From Sql Datareader?

Apr 2, 2010

I have an sql query with sql datareader. i put a for loop for the data reader. now when the data starts coming in from the query i want it to export to excel in the for loophere's my code

Try
Dim SqlStr As String = "", dr As SqlDataReader = Nothing
ConnectDB(Cnn)

[code].....

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Filling ListView With DataReader?

Mar 11, 2010

I am trying to fill a listView with data of a DataReader, this is the

Dim CMD As New OleDb.OleDbCommand
CMD.Connection = CN
CMD.CommandText = "select Name, DNI, Sum(Price) from ORDERS group by name, dni"
Dim miDataReader As OleDb.OleDbDataReader

[Code]...

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Get Number Of Row Returned By DataReader?

Jan 23, 2006

I have been playing around with datareader for a little while, and I can't figure out how to get the number of row returned? [code]...

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Go Back To The Previous Row Using DataReader On ASP.NET (VB)

Jun 18, 2010

How can I go back to the previous row using OleDbDataReader.

I know that DataReader just advance to the next row using DataReader.Read(), but how can I go back to the previous row. ???!!

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How To Convert A Datareader To Datatable

Feb 23, 2012

I have a question about converting a datareader to a datatable. In my code, I have a datareader created in one class and passed to another class that I want to convert it to a datatable.

When I do this, it does not seem to work, as the table remains empty. If I do the conversion in the same function, it works fine.

Its only when I pass the datareader to another function that it stops working. Is this because the dr is closed or something? How do I overcome this problem? Any help would be great.

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