The SelectCommand property has not been initialized before calling 'Fill - vb.net

Question

Im trying to upload some records from an excel file and got that error when uploaded the source to the server.
`sqlQuery = "Select * from [Sheet1$]"
oleConn = New OleDb.OleDbConnection
oleConn.ConnectionString = conString
If oleConn.State = ConnectionState.Closed Then oleConn.Open()
oleCmd = New OleDb.OleDbCommand(sqlQuery, oleConn)
oleCmd.Connection = oleConn
oleCmd.CommandText = "Select * from [Sheet1$]"'--tried to add this but gettin the same error
oleCmd.CommandType = CommandType.Text'--and this
oleDa = New OleDb.OleDbDataAdapter(oleCmd)
oleDa.SelectCommand = oleCmd
oleDa.Fill(oleDs)
oleCmd.Dispose()
If oleConn.State = ConnectionState.Open Then oleConn.Close()
Return oleDs`

Answer 1

Try,
For opening connection
If oleConn.State <> ConnectionState.Open Then
oleConn.Open()
End if
For closing
If oleConn.State <> ConnectionState.Closed Then
oleConn.State.Close()
End if

Answer 2

still same. is that probability crash on VS. before i install SDK for VS is run good. but after fail install SDK become like that.

Answer 3

Try This code
Private Sub buttonExecute_Click(sender As Object, e As EventArgs) Handles buttonExecute.Click
Try
' Fill the DataGridView and connection string TextBox
Dim FilePath As String = "C:\ExcelFile.xls" 'This is where file is located
Dim FileType As String = "*.xlsx" 'This what extinction that file have
Using connection As New OleDbConnection(GetConnectionString(FilePath, FileType))
connection.Open()
textBoxConnectionString.Text = GetConnectionString(FilePath, FileType)
Using adapter As New OleDbDataAdapter("Select * from [Sheet1$]", connection)
adapter.Fill(data)
End Using
End Using
Catch ex As Exception
' Display any errors
MessageBox.Show("[" & ex.[GetType]().Name & "] " & ex.Message & ex.StackTrace)
End Try
End Sub
Here method to getconiction string:
Function Excel_GetConnectionString(FilePath As String, FileType As String) As String
' Name of the Excel worksheet to open
Dim filename As String = FilePath
' Note: the Types array exactly matches the entries in openFileDialog1.Filter
' For Excel 2007 XML (*.xlsx)
' For Excel 2007 Binary (*.xlsb)
' For Excel 2007 Macro-enabled (*.xlsm)
' For Excel 97/2000/2003 (*.xls)
Dim Types As String() = {"Excel 12.0 Xml", "Excel 12.0", "Excel 12.0 Macro", "Excel 8.0", "Excel 5.0"}
' For Excel 5.0/95 (*.xls)
' Note: openFileDialog1.FilterIndex was saved into textBoxFilename.Tag
Dim Type As String = Types(CInt(FileType) - 1)
' True if the first row in the Excel data is a header (used for column names, not data)
Dim Header As Boolean = True
' True if columns containing different data types are treated as text
' (note that columns containing only integer types are still treated as integer, etc)
Dim TreatIntermixedAsText As Boolean = True
' Build the actual connection string
Dim builder As New OleDb.OleDbConnectionStringBuilder()
builder.DataSource = filename
If Type = "Excel 5.0" OrElse Type = "Excel 8.0" Then
builder.Provider = "Microsoft.Jet.OLEDB.4.0"
Else
builder.Provider = "Microsoft.ACE.OLEDB.12.0"
End If
builder("Extended Properties") = Type & ";HDR=" & (If(Header, "Yes", "No")) & ";IMEX=" & (If(TreatIntermixedAsText, "1", "0"))
' The "ACE" provider requires either Office 2007 or the following redistributable:
' Office 2007 Data Connectivity Components:
' http://www.microsoft.com/downloads/details.aspx?familyid=7554F536-8C28-4598-9B72-EF94E038C891&displaylang=en
' The "ACE" provider can be used for older types (e.g., Excel 8.0) as well.
' The connection strings used for Excel files are not clearly documented; see the following links for more information:
' Excel 2007 on ConnectionStrings.com:
' http://www.connectionstrings.com/excel-2007
' Excel on ConnectionStrings.com:
' http://www.connectionstrings.com/excel
' Microsoft OLE DB Provider for Microsoft Jet on MSDN:
' http://msdn.microsoft.com/en-us/library/ms810660.aspx
' KB247412 Methods for transferring data to Excel from Visual Basic:
' http://support.microsoft.com/kb/247412
' KB278973 ExcelADO demonstrates how to use ADO to read and write data in Excel workbooks:
' http://support.microsoft.com/kb/278973
' KB306023 How to transfer data to an Excel workbook by using Visual C# 2005 or Visual C# .NET:
' http://support.microsoft.com/kb/306023
' KB306572 How to query and display excel data by using ASP.NET, ADO.NET, and Visual C# .NET:
' http://support.microsoft.com/kb/306572
' KB316934 How to use ADO.NET to retrieve and modify records in an Excel workbook with Visual Basic .NET:
' http://support.microsoft.com/kb/316934
Return builder.ConnectionString
End Function