dotNETportal.cz

Dobrý den,

snažím se o zápis do SQL databáze. A vždy dostanu error:

The parameterized query '(@CurrentVLSN nvarchar(4000))SELECT COUNT (*) FROM [SenderLogica' expects the parameter '@CurrentVLSN', which was not supplied.

Omlouvám se za nejspíš stupidní dotaz, ale už asi tři dny si nevím rady a pořád zkouším.

Tady jsou kódy pro vytvoření tabulek a pro zápis:

Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient
Imports System.Timers
Imports System.DateTime
Module LogicalDiskInfo
    Public Function putSenderLogicalDisksInfo()
        'nastavení SQL spojení
        Dim ConnectionString As String = System.Configuration.ConfigurationManager.AppSettings("Databaze")
        Dim sqlConnection As New SqlClient.SqlConnection(ConnectionString)
        Dim sqlcmd As New SqlClient.SqlCommand
        Dim CountCurrentVLSN As Integer

        Dim mngmtClass As ManagementClass
        mngmtClass = New ManagementClass("Win32_LogicalDisk")
        Dim mngmtObject As ManagementObject
        For Each mngmtObject In mngmtClass.GetInstances()

            Dim sqlCommand As New SqlCommand("SELECT COUNT (*) FROM [SenderLogicalDisks] WHERE [SenderLogicalDiskVolumeSerialNumber] = @CurrentVLSN", sqlConnection)

            sqlCommand.Parameters.AddWithValue("@CurrentVLSN", mngmtObject("VolumeSerialNumber")) 'pitcho tu je nejaky problemecek


            sqlConnection.Open()
            CountCurrentVLSN = CInt(sqlCommand.ExecuteScalar())
            sqlConnection.Close()

            If Not CountCurrentVLSN = 0 Then        'jednotka exituje
                sqlcmd = New SqlCommand("UPDATE [SenderLogicalDisks] SET [SenderUUID] = @SenderUUID, [SenderLogicalDiskName] = @SenderLogicalDiskName, [SenderLogicalDiskType] = @SenderLogicalDiskType, [SenderLogicalDiskFileSystem] = @SenderLogicalDiskFileSystem, [SenderLogicalDiskSize] = @SenderLogicalDiskSize, [SenderLogicalDiskFreeSpace] = @SenderLogicalDiskFreeSpace WHERE [SenderLogicalDiskVolumeSerialNumber] = @SenderLogicalDiskVolumeSerialNumber", sqlConnection)
            Else                                    'jednotka neexistuje
                sqlcmd = New SqlCommand("INSERT INTO [SenderLogicalDisks] ([SenderUUID], [SenderLogicalDiskName], [SenderLogicalDiskType], [SenderLogicalDiskFileSystem], [SenderLogicalDiskSize], [SenderLogicalDiskFreeSpace], [SenderLogicalDiskVolumeSerialNumber]) VALUES (@SenderUUID, @SenderLogicalDiskName, @SenderLogicalDiskType, @SenderLogicalDiskFileSystem, @SenderLogicalDiskSize, @SenderLogicalDiskFreeSpace, @SenderLogicalDiskVolumeSerialNumber)", sqlConnection)
            End If

            sqlcmd.Parameters.AddWithValue("@SenderUUID", getLocalUUID())
            'sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskName", mngmtObject("Name"))
            'sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskType", mngmtObject("DriveType"))
            'sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskFileSystem", mngmtObject("FileSystem"))
            'sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskSize", mngmtObject("Size"))
            'sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskFreeSpace", mngmtObject("FreeSpace"))
            sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskVolumeSerialNumber", mngmtObject("VolumeSerialNumber"))


            sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskName", "")
            sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskType", "")
            sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskFileSystem", "")
            sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskSize", "")
            sqlcmd.Parameters.AddWithValue("@SenderLogicalDiskFreeSpace", "")


            sqlConnection.Open()
            sqlcmd.ExecuteNonQuery()
            sqlConnection.Close()

        Next

        Return 0
    End Function

End Module

Imports System
Imports System.Management
Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient
Module Module1
    Sub Main()
        Dim ConnectionString As String = System.Configuration.ConfigurationManager.AppSettings("TestovaciDatabaze")

        Dim sqlConnection As New SqlClient.SqlConnection(ConnectionString) ' inicializace objektu spojení na databázi

        Dim sqlCreateTableSenders As New SqlCommand("CREATE TABLE [Senders] ([SenderID] INT NOT NULL PRIMARY KEY IDENTITY(1,1),[SenderUUID] VARCHAR(100) NOT NULL, [SenderDNSHostName] VARCHAR(100) NOT NULL,[SenderDomain] VARCHAR(100) NOT NULL, [SenderLastContact] DATETIME,[SenderManufacturer] VARCHAR(100) NOT NULL,[SenderModel] VARCHAR(100) NOT NULL,[SenderOS] VARCHAR(50))", sqlConnection)
        Dim sqlCreateTableSendersLogicalDisks As New SqlCommand("CREATE TABLE [SenderLogicalDisks] ([SenderLogicalDiskID] INT NOT NULL PRIMARY KEY IDENTITY(1,1),[SenderUUID] VARCHAR(100), [SenderLogicalDiskName] VARCHAR(5),[SenderLogicalDiskType] VARCHAR(100), [SenderLogicalDiskFileSystem] VARCHAR(20),[SenderLogicalDiskSize] BIGINT,[SenderLogicalDiskFreeSpace] BIGINT,[SenderLogicalDiskVolumeSerialNumber] VARCHAR(11))", sqlConnection)

        sqlConnection.Open() ' pomocí dat z ConnectionStringu spojení otevřeme

        sqlCreateTableSenders.ExecuteNonQuery()
        sqlCreateTableSendersLogicalDisks.ExecuteNonQuery()


        sqlConnection.Close() ' a zase uzavřeme




        Console.Write("Press any key...")
        Console.ReadKey()
    End Sub
End Module

Zkuste převést parametr na string

mngmtObject("VolumeSerialNumber").ToString()

V tom případě je na stejném řádku chyba:

NullReferenceException was unhandled

Object reference not set to an instance of an object.

A určitě se vám daná proměnná něčím plní? Možná bych trochu opravil kód pro testování a parametr načítal postupně,dal si tak i breakpointy a sledoval kde je chyba.

omlouvám se za ten komentar, nechal jsem spoluzaka at mi napise, ze to tam nejde a vypne pocitac uz jsem to nekontroloval