?
Solved

dataset error

Posted on 2006-06-23
3
Medium Priority
?
203 Views
Last Modified: 2010-04-23
Hello Experts,

I have a question about datasets. I connect to several databases  and load the query result into a dataset that I write to an XML file. The first connection works fine but when I try it a second time in the same sub I get this error:

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



Posted below is the code that executes:

Try
            conn.Open()
            mycommand.Connection = conn

            mycommand.CommandText = "SELECT * FROM test WHERE testNum= " & Textbox1.Text & " AND Type = 'Contract'"
            myRead = mycommand.ExecuteReader

            While myRead.Read()
                ...assign variables...
            End While

            myRead.Close()
            conn.Close()

            myAdapter.SelectCommand = mycommand
            myAdapter.Fill(myData)
            myData.WriteXml("C:\Dataset.xml", XmlWriteMode.WriteSchema)
            myData.Clear()

            '****************Second connection*********************

            conn.ConnectionString = "server=192.16.......~"
            conn.Open()
            mycommand.Connection = conn
            mycommand.CommandText = "SELECT * FROM test2 WHERE test2Num= " & Textbox1.Text
            myRead = mycommand.ExecuteReader

            While myRead.Read()
              ...assign varibales...
            End While

            myAdapter.SelectCommand = mycommand
            myAdapter.Fill(myData)
            myData.WriteXml("C:\totalNumberDataset.xml", XmlWriteMode.WriteSchema) <----HERE is where the exception is thrown

        Catch ex As MySqlException
            MessageBox.Show(ex.Message)
        Finally
            conn.Close()
        End Try

Any help is greatly appreciated


Thanks,

Zac
0
Comment
Question by:sacul
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 7

Accepted Solution

by:
pradeepsudharsan earned 1000 total points
ID: 16969124
While myRead.Read()
              ...assign varibales...
            End While
myRead.Close() 'Close the reader and use adapter
0
 
LVL 7

Expert Comment

by:pradeepsudharsan
ID: 16969177
       myRead.Close()
            conn.Close()
You missed these lines in Second connection

While myRead.Read()
              ...assign varibales...
            End While
myRead.Close() 'Close the reader and use adapter
 conn.Close() is not needed
0
 
LVL 1

Author Comment

by:sacul
ID: 16970105
Awesome...

I just missed that part. You spend enough hours looking at it and you go code blind thats for sure

Thanks for the help.

Thanks,

Zac
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This tutorial demonstrates one way to create an application that runs without any Forms but still has a GUI presence via an Icon in the System Tray. The magic lies in Inheriting from the ApplicationContext Class and passing that to Application.Ru…
Microsoft Reports are based on a report definition, which is an XML file that describes data and layout for the report, with a different extension. You can create a client-side report definition language (*.rdlc) file with Visual Studio, and build g…
In this video, Percona Director of Solution Engineering Jon Tobin discusses the function and features of Percona Server for MongoDB. How Percona can help Percona can help you determine if Percona Server for MongoDB is the right solution for …
In this video, Percona Solutions Engineer Barrett Chambers discusses some of the basic syntax differences between MySQL and MongoDB. To learn more check out our webinar on MongoDB administration for MySQL DBA: https://www.percona.com/resources/we…
Suggested Courses

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question