C#

There is something that escapes me ...
This is the code for the form1
(using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.SQLite;

namespace Acode
{
    public partial class Form1: Form
    {
        public Form1 ()
        {
            InitializeComponent ();
           
        }
        private SQLiteConnection sql_con;
private SQLiteCommand sql_cmd;
        private SQLiteDataAdapter DB;
private DataSet DS = new DataSet ();
private DataTable DT = new DataTable ();

        private void setConnection ()
{
sql_con = new SQLiteConnection (@ "Data Source = DBcode.db; Version = 3; New =; Compress = True;");
}

        private void LoadData ()
        {
            SetConnection ();
            sql_con.Open ();
            sql_cmd = sql_con.CreateCommand ();
            string CommandText = "select * from InfoCode";
            DB = new SQLiteDataAdapter (CommandText, sql_con);
            DS.Reset ();
            DB.Fill (DS);
            DT = DS.Tables [0];
            dataGridView1.DataSource = DT;
            sql_con.Close ();
        }

        private void Form1_Load (object sender, EventArgs e)
        {
            LoadData ();

        }

        private void ExecuteQuery (String txtQuery)
{
        SetConnection ();
sql_con.Open ();
sql_cmd = sql_con.CreateCommand ();
sql_cmd.CommandText = txtQuery;
sql_cmd.ExecuteNonQuery ();
sql_con.Close ();
}

        public static string randomstring (int length)
        {
            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWYZ0123456789";
            Random random = new Random ();
            return new string (Enumerable.Repeat (floats, length) .Select (s => s [random.Next (s.Length)]). ToArray ());
        }
        private void btnGenerer_Click (object sender, EventArgs e)
        {
           
            lblDisplay.Text = randomstring (4);
            txtAfficPrice.Text = "100";
        }

        private void button1_Click (object sender, EventArgs e)
        {
            lblDisplay.Text = randomstring (5);
            txtAffichPrice.Text = "300";
        }

        private void button2_Click (object sender, EventArgs e)
        {
            lblDisplay.Text = randomstring (6);
            txtAffichPrice.Text = "500";
        }

       
        private void btnRegister_Click (object sender, EventArgs e)
        {
            if (lblDisplay.Text == "")
            {
                MessageBox.Show ("Please generate the code");
            }
            else
            {
                string txtQuery = "insert into InfoCode (Code, DateCode, PriceCode) values ​​('" + lblDisplay.Text + "', '" + dateTimePicker1.Text + "', '" + txtAfficePrice.Text + "')";
                ExecuteQuery (txtQuery);
                LoadData ();
                MessageBox.Show ("Registration completed successfully");
                lblDisplay.Text = "";
                groupBoxGenerer.Enabled = false;
                btnSave.Enabled = false;
                This.Refresh ();
            }
            
        }

        private void btnAdd_Click (object sender, EventArgs e)
        {
            groupBoxGenerer.Enabled = true;
            btnSave.Enabled = true;
        }

        private void exitToolStripMenuItem_Click (object sender, EventArgs e)
        {
            this.Close ();
        }

        private void codeSOLDToolStripMenuItem_Click (object sender, EventArgs e)
        {
            FrmCodeSold frmcodevended = new FrmCodeSold ();
            frmcodevendu.Show ();
            this.Hide ();
    
        }

        private void pointToolStripMenuItem_Click (object sender, EventArgs e)
        {
            FrmPointJournal pointQ = new FrmPointJournal ();
            pointQ.Show ();
            this.Hide ();
        }
    }
}
)

and I wish I could print all the recordings from there via another form
I have a faith done but with access and this faith I use SQlite but as I emphasize them I do not see the data SQlite in my data source.

string txtQuery = "insert into InfoCode (Code, DateCode, PriceCode) values ​​('" + lblDisplay.Text + "', '" + dateTimePicker1.Text + "', '" + txtAfficePrice.Text + "')";

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

SELECT * FROM MyTable WHERE StreetAddress = 'x';

DROP TABLE MyTable;

--'

dataGridView1.DataSource = DT;

private void ExecuteQuery (String txtQuery)
{
        SetConnection ();
sql_con.Open ();
sql_cmd = sql_con.CreateCommand ();
sql_cmd.CommandText = txtQuery;
sql_cmd.ExecuteNonQuery ();

Thank you for all these tips for me will be a pulse to my learning. it's in my research that I found but what do you recommend to me?
I correct this error before talking about printing or after?

Frankly thank you for giving me your time. give me a few minutes just the time for me to redo my connection and I come back to you.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.SQLite;

namespace Acode
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
           
        }
        private SQLiteConnection sql_con;
	    private SQLiteCommand sql_cmd;
        private SQLiteDataAdapter DB;
	    private DataSet DS = new DataSet();
	    private DataTable DT = new DataTable();

        private void setConnection()
	    {
	    sql_con = new SQLiteConnection(@"Data Source=DBcode.db; Version=3;New=;Compress=True;");
	    }

        private void LoadData()
        {
            setConnection();
            sql_con.Open();
            sql_cmd = sql_con.CreateCommand();
            sql_cmd.CommandText = "select * from InfoCode";
            DB = new SQLiteDataAdapter(sql_cmd.CommandText, sql_con);
            DS.Reset();
            DB.Fill(DS);
            DT = DS.Tables[0];
            dataGridView1.DataSource = DT;
            sql_con.Close();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            LoadData();

        }

        private void ExecuteQuery()
	    {
        setConnection();
	    sql_con.Open();
	    sql_cmd = sql_con.CreateCommand();
	    //sql_cmd.CommandText = txtQuery;
	    //sql_cmd.ExecuteNonQuery();
	    sql_con.Close();
	    }

        public static string randomstring(int length)
        {
            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWYZ0123456789";
            Random random = new Random();
            return new string(Enumerable.Repeat(chars, length).Select(s => s[random.Next(s.Length)]).ToArray());
        }
        private void btnGenerer_Click(object sender, EventArgs e)
        {
           
            lblAffichage.Text = randomstring(4);
            txtAffichPrix.Text = "100";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            lblAffichage.Text = randomstring(5);
            txtAffichPrix.Text = "300";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            lblAffichage.Text = randomstring(6);
            txtAffichPrix.Text = "500";
        }

       
        private void btnEnregistrer_Click(object sender, EventArgs e)
        {
            if (lblAffichage.Text =="")
            {
                MessageBox.Show("Merci de bien vouloir générer le code");
            }
            else
            {
                sql_cmd.CommandText = "insert into InfoCode (Code, DateCode, PrixCode) values('" + lblAffichage.Text + "' , '" + dateTimePicker1.Text + "' , '" + txtAffichPrix.Text + "')";
                sql_cmd.ExecuteNonQuery();
                LoadData();
                MessageBox.Show("Enregistrement effectué avec succès");
                lblAffichage.Text = "";
                groupBoxGenerer.Enabled = false;
                btnEnregistrer.Enabled = false;
                this.Refresh();
            }
            
        }

        private void btnAjouter_Click(object sender, EventArgs e)
        {
            groupBoxGenerer.Enabled = true;
            btnEnregistrer.Enabled = true;
        }

        private void quitterToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void codeVenduToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FrmCodeVendu frmcodevendu=new FrmCodeVendu();
            frmcodevendu.Show();
            this.Hide();
    
        }

        private void pointToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FrmPointJournalier pointQ = new FrmPointJournalier();
            pointQ.Show();
            this.Hide();
        }
    }
}
I receive an error message: Database is not open

sql_cmd.CommandText = "insert into InfoCode (Code, DateCode, PrixCode) values('" + lblAffichage.Text + "' , '" + dateTimePicker1.Text + "' , '" + txtAffichPrix.Text + "')";

but what should I do? since you asked me to correct the error. can you tell me more so that I can understand

using (SqlConnection con = new SqlConnection(strConnect))
    {
    con.Open();
    using (SqlCommand cmd = new SqlCommand("INSERT INTO myTable (myColumn1, myColumn2) VALUES (@C1, @C2)", con))
        {
        cmd.Parameters.AddWithValue("@C1", myValueForColumn1);
        cmd.Parameters.AddWithValue("@C2", myValueForColumn2);
        cmd.ExecuteNonQuery();
        }
    }

i will do it aisin and come back to you, thanks for your help

 private void btnAdd_Click(object sender, EventArgs e)
        {
            if (lblAffichage.Text == "")
            {
                MessageBox.Show("Merci de bien vouloir générer le code");
            }
            else
            {
                using (SQLiteConnection con = new SQLiteConnection(sql_con))
                {
                    con.Open();
                    using (SQLiteCommand cmd = new SQLiteCommand("INSERT INTO InfoCode (Code, DateCode, PrixCode) VALUES (@Code, @DateCode, @PrixCode)", con))
                    {
                        cmd.Parameters.AddWithValue("@Code", lblAffichage.Text);
                        cmd.Parameters.AddWithValue("@DateCode", dateTimePicker1.Text);
                        cmd.Parameters.AddWithValue("@PrixCode", txtAffichPrix.Text);
                        cmd.ExecuteNonQuery();
                    }
                    LoadData();
                    MessageBox.Show("Enregistrement effectué avec succès");
                    lblAffichage.Text = "";
                    groupBoxGenerer.Enabled = false;
                    btnEnregistrer.Enabled = false;
                    this.Refresh();
                }
            }
        }
Thank you very much for your help ... it works

Hello sir I was able to find a solution to print, I'm going through a DataSet: I connected the DataSet to my database

here is the code: {
            setConnection();
            sql_con.Open();
            sql_cmd = sql_con.CreateCommand();
            string CommandText = "select * from InfoCode";
            DB = new SQLiteDataAdapter(CommandText, sql_con);
            DS.Reset();
            CrystalReportImprimCode x = new CrystalReportImprimCode();
            DBset dt = new DBset();
            DB.Fill(dt.InfoCode);
            x.SetDataSource((DataTable)dt.InfoCode);
            crystalReportViewer1.ReportSource = x;
            crystalReportViewer1.Refresh();
            sql_con.Close();
        }

ibrahimayhans wrote:

SerialPort.ReadExisting () Returns an Incomplete Result.