How can I save this in a database?

Question

I have a problem when trying to insert data into a sql database. I hope someone can help me. Every time I click on button2 a MessageBox appeares and is saying:

Error while inserting record in table...'lines' is not a recognized built-in function name.

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

    Dim con As New SqlConnection
    Dim cmd As New SqlCommand
    Using sr As New System.IO.StreamReader("C:\Users\klaasjelle\Documents\Visual Studio 2017\Projects\WindowsApp2\WindowsApp2\bin\Debug\Images.txt")

        Try
            con.ConnectionString = "Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\klaasjelle\Documents\visual studio 2017\Projects\WindowsApp3\WindowsApp3\Niks.mdf;Integrated Security=True"

            con.Open()
            cmd.Connection = con

            cmd.CommandText = "INSERT INTO Data (FilePath, ImageSize, ImageSide) VALUES (ListViewItem(lines(0)), lvItem.SubItem.Add(lines(1)), lvItem.SubItem.Add(lines(2)))"

            cmd.ExecuteNonQuery()

        Catch ex As Exception
            MessageBox.Show("Error while inserting record on table..." & ex.Message, "Insert Records")

        Finally
            con.Close()
        End Try
    End Using
End Sub
End Class

As I said. Every time I click on Button2, it is saying:

Error while inserting record on table...'lines' is not a recognized built-in function name.

Can someone help me please

As suggested here is also the code that belongs to Button1_Click

   Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

    Using sr As New System.IO.StreamReader("C:\Users\klaasjelle\Documents\Visual Studio 2017\Projects\WindowsApp2\WindowsApp2\bin\Debug\Images.txt")

        While Not sr.EndOfStream

            Dim lines As String() = sr.ReadLine.Split(New String() {","}, StringSplitOptions.RemoveEmptyEntries)

            Dim lvItem As New ListViewItem(lines(0))
            lvItem.SubItems.Add(lines(1))
            lvItem.SubItems.Add(lines(2))

            ListView1.Items.Add(lvItem)

        End While

    End Using

    ListView1.AutoResizeColumns(ColumnHeaderAutoResizeStyle.ColumnContent)
    ListView1.AutoResizeColumns(ColumnHeaderAutoResizeStyle.HeaderSize)

End Sub

Answer 1

You are passing a string literal to your INSERT statement. This string is not the ListView item but simply a string that the database engine try to parse knowning anything at all about your list view and lines array.

Instead you should use a parameterized query

cmd.CommandText = "INSERT INTO Data (FilePath, ImageSize, ImageSide) 
                  VALUES (@path, @size, @side)"
cmd.Parameters.Add("@path", SqlDbType.NVarChar).Value = ListViewItem(lines(0))
cmd.Parameters.Add("@size", SqlDbType.NVarChar).Value = ListViewItem(lines(1))
cmd.Parameters.Add("@side", SqlDbType.NVarChar).Value = ListViewItem(lines(2))
....

I assume that your database fields are of type NVarChar, if not then change the SqlDbType enum to the correct value and parse the input ListViewItem to the correct datatype

I am limiting my answer to the database problem, but your code seems to be incomplete. Where is defined the lines array? How do you get the reference to the ListViewItem?

Following your edit:
The variables are defined inside the button1_click event, and thus you cannot use them inside the button2_click event. You need to read the content of you listview and extract the info that you have added in the button1_click.

Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button1.Click
    using con As New SqlConnection
    using cmd As New SqlCommand

       con.ConnectionString = "....."
       con.Open()
       cmd.Connection = con



       cmd.Parameters.Add("@path", SqlDbType.NVarChar)
       cmd.Parameters.Add("@size", SqlDbType.NVarChar)
       cmd.Parameters.Add("@side", SqlDbType.NVarChar)
       cmd.CommandText = "INSERT INTO Data (FilePath, ImageSize, ImageSide) 
                          VALUES (@path, @size, @side)"


       For Each item as ListViewItem in ListView1
            Dim path = item.Text
            Dim size = item.SubItems(1)
            Dim side = item.SubItems(2)

            ' Now you have the variables to insert in the database
            cmd.Parameters("@path").Value = path
            cmd.Parameters("@size").Value = size
            cmd.Parameters("@side").Value = side
            cmd.ExecuteNonQuery()
        Next
    End Using
    End Using
End Sub

Note that I changed a bit the logic of the previous example. Now I create the connection and the command in a Using block. This will save me to explicitly close and destroy these commands. Then I define the parameters outside the loop while inside the loop I change only the value. (A simple optimization with no great benefits unless you have thousands of Items in your listview) Finally I loop over every item in the listview and extract the info that you want to insert in the database from each ListViewItem

Answer 2

You're trying to execute VB code in SQL. Which of course won't work. Get your values in your VB code and then add them as parameters to the SQL command. Something like this:

cmd.CommandText = "INSERT INTO Data (FilePath, ImageSize, ImageSide) VALUES (@FilePath, @ImageSize, @ImageSide)"
command.Parameters.Add("@FilePath", SqlDbType.NVarChar) 'Guessing on the type here
command.Parameters("@FilePath").Value = ListViewItem(lines(0))
' Repeat for the other two parameters, using the appropriate SqlDbType values for each

cmd.ExecuteNonQuery()