SQL Server Express 2008 connection problem

[Heather5]

I am developing an application in VB.Net with a database in SQL Server Express 2008. I made my connection

'definition of connection variables
Dim user As String
        Dim mdp As String
        Dim bdd As String
        Dim server As String
        Dim connstring As String
 
        'recovery of connection variables
        user = "sa"
        mdp = ""
        bdd = "elect_test_yln"
        server = " .\SQLEXPRESS"
 
        'filling of the variable to start the connection
        connstring = "Persist Security Info = true; Integrated Security = SSPI; Data Source = " & server & "; Database = " & bdd & "; User ID = " & user & "; Password = " & mdp & ";"
 
        'connection has the database with error handling
        Try
            conn = New SqlConnection(connstring)
            conn.Open()
        Catch e As Exception
            MsgBox("The following error occurred: " & e.Message)
        Finally : conn.Close()
        End Try

Loading there is no problem but that I perform a query

data_parent = "select numfile, label from file"
Dim request_parent As New SqlCommand(data_parent)
reader_parent = request_parent.ExecuteReader
reader_parent.Read()

I receive the following error message that points to "reader_parent = request_parent.ExecuteReader"

ExecuteReader: Connection property has not been initialized.

Someone has an idea as it stops to do that (and quickly if possible)

[Reegan]

By learning to read errors and considering/trying to understand a little bit. The documentation may also help: MSDN tutorials ADO.Net, ....

For

ExecuteReader: Connection property has not been initialized.

ExecuteReader method is a DbCommand objects (SqlCommand OdbcCommand ...). The error indicates that when calling this method, the Connection property has not been initialized. Logic since command runs over a connection.

So on your SqlCommand object you must have something to initialize this connection, what you do not. If necessary, the link to the MSDN for the class.

[Heather5]

Thank you for responding so quickly! I blocked the above this morning and I searched msdn and company without really finding any happiness. Ok I'll look at it more closely.

[CodGuru]

The ObjetConnection corresponds to Conn in your case, its your variable connection. Here are the items that need to be reported for the connection:

Private rqSql As String 'SQL string String 
Private cnxString As String 'SQL string used to accommodate the Chemain the SQL database 
Private CNX As System.Data.SqlClient.SqlConnection 'Subject connection string that contains the connection string 
CMD Target As System.Data.SqlClient.SqlCommand 'contains the connection over the SQL query 
Private da As System.Data.SqlClient.SqlDataAdapter 'Data fit, subject only connected program 
Private DS As System.Data.DataSet object cache that contains all records from the output of CMD