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dataset error

Posted on 2006-06-23
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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
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Comment
Question by:sacul
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3 Comments
 
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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
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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
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