小编Gid*_*eon的帖子

我使用以下内容为变量设置日期值:

    Dim someDate As DateTime = Date.Today.AddDays(1) 

    nextMonday = someDate
    While nextMonday.DayOfWeek <> DayOfWeek.Monday
        nextMonday = nextMonday.AddDays(1)
    End While

然后,我使用以下内容将日期插入SQL Server表:

   Private Sub CButton1_ClickButtonArea(Sender As Object, e As MouseEventArgs) Handles CButton1.ClickButtonArea
    Dim doenditstring As String = "INSERT INTO Parsversoeke (ma_datum,di_datum)  " & _
                                     "VALUES (" & _
                                       "'" & nextMonday & "'," & _
                                     "'" & nextTuesday & "')" 

    cnn.Open()
    Dim aksie As New SqlClient.SqlCommand(doenditstring, cnn)

    aksie.ExecuteNonQuery()

    cnn.Close()

它有效,除了我只能在两个日期做.之后我收到以下错误:

从字符串转换日期和/或时间时转换失败

有谁知道我为什么会收到错误？

我使用以下SQL语句:

      Dim strSql5 As String = "SELECT  * FROM dbo.ontledings " & _
                                " where plaasblok =  @plaasblokparsversoeke " & _
                                " and analisedatum  =  @laastedatum"


    cnn.Open()
    Dim aksie2 As New SqlClient.SqlCommand(strSql5, cnn)
    aksie2.Parameters.Add("@plaasblokparsversoeke", SqlDbType.VarChar).Value = plaasblokparsversoeke
    aksie2.Parameters.Add("@laastedatum", SqlDbType.Date).Value = laastedatum
    aksie2.ExecuteNonQuery()
    cnn.Close()

我想填充像这样的数据表:

    Dim dtb5 As New DataTable
    dtb5.Clear()

    Using cnn As New SqlConnection("Data Source=GIDEON-E-LAPTOP\SQLEXPRESS2014;Initial Catalog=SkeduleringDatabasis;Integrated Security=True")
        cnn.Open()

        Using dad5 As New SqlDataAdapter(strSql5, cnn)

            dad5.Fill(dtb5)
        End Using
        cnn.Close()
    End Using

我收到以下错误消息:必须声明标量变量"@plaasblokparsversoeke"

我无法弄清楚在哪里以及如何声明标量变量.

错误发生在以下行:dad5.Fill(dtb5)

问候

我想用同一行另一列中的值替换所有具有 NULL 值的值。

我尝试了不同的 sql 语句，但没有成功。

问候