错误“ExecuteReader:连接属性尚未初始化。”
问题描述:
这是我的代码。我似乎无法弄清楚是什么导致了这个错误。该错误本身指向Do While myReader.read
代码行,但我不确定那是什么导致了问题。错误“ExecuteReader:连接属性尚未初始化。”
这里有一个更详细的错误信息:
的ExecuteReader:连接属性尚未初始化。在在system.data.oledb.oledbcommand.validateconnectionandtransaction system.data.oledb.oledbcommand.validateconnection(串法)(串法)
代码:
Imports System.Data.OleDb
Imports System.Data
Partial Class Customer_6_OrderHistory
Inherits System.Web.UI.Page
Private myDB As OleDbConnection
Private sqlCmd As OleDbCommand
Private myReader As OleDbDataReader
Private myConnection As String = ConfigurationManager.ConnectionStrings("ConnString10").ToString
Private myDataFile As String = ConfigurationSettings.AppSettings("DBFile")
Private LegoNameList As New ArrayList
Private ShipmentDateList As New ArrayList
Private CostList As New ArrayList
Private NumberPurchasedList As New ArrayList
Private RecipientList As New ArrayList
Private TotalCostList As New ArrayList
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
myDB = New OleDbConnection(myConnection)
sqlCmd = New OleDbCommand("exec qry_OrderHistory")
sqlCmd.Parameters.AddWithValue("@CustomerName", Session("myCart").GetCustomerName())
Try
myDB.Open()
myReader = sqlCmd.ExecuteReader
Do While myReader.Read
LegoNameList.Add(myReader("Lego Name"))
ShipmentDateList.Add(myReader("Date"))
CostList.Add(myReader("Cost"))
NumberPurchasedList.Add(myReader("Number Purchased"))
RecipientList.Add(myReader("Recipient"))
TotalCostList.Add(myReader("Total Cost"))
Loop
myReader.Close()
Catch ex As Exception
MsgBox(ex.ToString)
Finally
myDB.Close()
End Try
Dim myDataTable As New DataTable
myDataTable.Columns.Add("Lego Name")
myDataTable.Columns.Add("Date")
myDataTable.Columns.Add("Cost")
myDataTable.Columns.Add("Number Purchased")
myDataTable.Columns.Add("Recipient")
myDataTable.Columns.Add("Total Cost")
For i = 0 To LegoNameList.Count - 1
Dim myRow As DataRow = myDataTable.NewRow
myRow.Item("Lego Name") = LegoNameList.Item(i)
myRow.Item("Date") = FormatDateTime(ShipmentDateList.Item(i), DateFormat.ShortDate)
myRow.Item("Cost") = FormatCurrency(CostList.Item(i), 2, TriState.True, TriState.False, TriState.True)
myRow.Item("Number Purchased") = NumberPurchasedList.Item(i)
myRow.Item("Recipient") = RecipientList.Item(i)
myRow.Item("Total Cost") = FormatCurrency(TotalCostList.Item(i), 2, TriState.True, TriState.False, TriState.True)
myDataTable.Rows.Add(myRow)
Next
gvwOrderHistory.DataSource = myDataTable
gvwOrderHistory.DataBind()
End Sub
End Class
答
你必须初始化实例连体myConnection
之前使用它
答
您已创建您的连接,然后您创建您的命令,但您永远不会将连接分配给您的命令,这就是为什么你会收到错误。您可以连接分配给您的OleDbCommand
,像这样:
sqlCmd.Connection = myDB
或者你可以在OleDbCommand
构造函数中指定,像这样:
sqlCmd = New OleDbCommand("exec qry_OrderHistory", myDB)
然后你就可以打开连接并执行命令。
+0
非常感谢!我可以通过使用 'sqlCmd = New OleDbCommand(“exec qry_OrderHistory”,myDB)'来修复错误 – JStew 2013-03-24 14:49:56
你永远不会分配你的连接到OleDBCommand,这就是为什么你会收到错误。尝试类似于'sqlCmd.Connection = myDB'或'sqlCommand = New OleDbCommand(“exec qry_OrderHistory”,myDB)' – Tim 2013-03-24 05:54:16
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