Question

我遇到CheckedListBox问题。如何将SelectedValues转换为更新查询？

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    Dim promozione As String

    dest = "INSERT INTO dbo.dest " &
               "([ID], [Cod], [SellIn], [SellOut]) " &
               "VALUES (@ID, @Cod, @SellIn, @SellOut)"

    Dim ins As New SqlDataAdapter(dest, con)
    Dim run As New SqlCommand(dest, con)
    con.Open()

    For Each Cod In CheckedListBox1.CheckedItems()
        run.Parameters.Add(New SqlParameter("@ID", ComboBox1.SelectedValue))
        run.Parameters.Add(New SqlParameter("@Cod", CheckedListBox1.SelectedValue))
        run.Parameters.Add(New SqlParameter("@SellIn", DateTimePicker1.Text))
        run.Parameters.Add(New SqlParameter("@SellOut", DateTimePicker2.Text))
        run.ExecuteNonQuery()
    Next

    con.Close()
End Sub

单击Button2时，将返回错误：

System.Data.dll中的'System.Data.SqlClient.SqlException'已经声明了变量名'@ID'。

Answer 1

您应该清除每次迭代的参数集合，我相信如下所示。实际上，更好的方法是在循环外创建这些参数，然后在每次迭代中设置它们的值。

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    Dim promozione As String

    dest = "INSERT INTO dbo.dest " &
                 "([ID], [Cod], [SellIn], [SellOut]) " &
                 "VALUES (@ID, @Cod, @SellIn, @SellOut)"

    Dim ins As New SqlDataAdapter(dest, con)
    Dim run As New SqlCommand(dest, con)



        con.Open()

        For Each Cod In CheckedListBox1.CheckedItems()
            run.Parameters.Clear()
            run.Parameters.Add(New SqlParameter("@ID", ComboBox1.SelectedValue))
            run.Parameters.Add(New SqlParameter("@Cod", CheckedListBox1.SelectedValue))
            run.Parameters.Add(New SqlParameter("@SellIn", DateTimePicker1.Text))
            run.Parameters.Add(New SqlParameter("@SellOut", DateTimePicker2.Text))
            run.ExecuteNonQuery()
        Next

        con.Close()

End Sub

Answer 2

如何从CHECKEDLISTBOX中插入SQL QUERY多个选定项目！两天后，这就是解决方案：

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    Dim dest As String

    dest = "INSERT INTO dbo.dest " &
                 "([ID], [Cod], [SellIn], [SellOut]) " &
                 "VALUES (@ID, @Cod, @SellIn, @SellOut)"

    Dim ins As New SqlDataAdapter(dest, con)
    Dim run As New SqlCommand(dest, con)



        con.Open()

        For Each Cod As DataRowView In CheckedListBox1.CheckedItems()
            run.Parameters.Clear()
            run.Parameters.Add(New SqlParameter("@ID", ComboBox1.SelectedValue))
            run.Parameters.Add(New SqlParameter("@Cod", Cod("IDCod"))) '<------ IDCods are the CheckedListBox1.ValueMembers'
            run.Parameters.Add(New SqlParameter("@SellIn", DateTimePicker1.Text))
            run.Parameters.Add(New SqlParameter("@SellOut", DateTimePicker2.Text))
            run.ExecuteNonQuery()
        Next

        con.Close()

End Sub

从CheckedListBox中检索SelectedValue并插入到SQL Server表中

2 个答案: