Asp.net 连接属性尚未正确初始化

Im在command2.ExecuteOnQuery（）上收到“连接属性未正确初始化”错误消息

我有一个SQL查询，它在网格视图中显示其结果（仅一个结果）。我正在尝试获取此结果，以使用SQL查询的此特定结果更新数据库

    Dim staffid = TextBox1.Text
    Dim conn As New SqlConnection
    conn.ConnectionString = SqlDataSource1.ConnectionString

    Dim command1 As New SqlCommand("SELECT StaffDetails.StaffID, SUM(HolidayRequests.RequestTotalDays) AS Expr1, HolidayEntitlement.HoldayEntitlementID, HolidayEntitlement.UserName FROM HolidayRequests INNER JOIN StaffDetails ON HolidayRequests.Username = StaffDetails.UserName INNER JOIN HolidayEntitlement ON StaffDetails.UserName = HolidayEntitlement.UserName WHERE (StaffDetails.StaffID = staffID) GROUP BY StaffDetails.StaffID, HolidayRequests.ApprovalStatus, HolidayEntitlement.HoldayEntitlementID, HolidayEntitlement.UserName HAVING (HolidayRequests.ApprovalStatus = N'approved')", conn)
    Dim command2 As New SqlCommand()
    conn.Open()
    Dim rdr As SqlDataReader
    rdr = command1.ExecuteReader
    Dim UpdateQuery As String
    While (rdr.Read())

        UpdateQuery = "UPDATE HolidayEntitlement set Holiday_Taken = @Expr1 WHERE HolidayEntitlementID = @HolidayEntitlementID"
        command2.Parameters.AddWithValue("@Expr1", rdr("Expr1").ToString())

        'run update query

        command2.CommandText = UpdateQuery
        command2.ExecuteNonQuery()

End while

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SqlCommand

需要指定一个

除此之外，您还应该查看（隐式关闭/处理连接）。这应该用于实现的每个类

command2.Connection = conn

Using conn = New SqlConnection(SqlDataSource1.ConnectionString)
    Using command1 = new SqlCommand(sql, conn)
        ' insert your code here .... '
    End Using
End Using