จะ Insert ข้อมูล ลง ตารางใน Database ผ่าน form ของ C#

            SqlCeConnection myConnection = default(SqlCeConnection);
            //myConnection = new SqlCeConnection("Data Source =" + (System.IO.Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase ) + "\\AppDatabase1.sdf;"));
            myConnection = new SqlCeConnection("Data Source =C:\\WindowsFormsApplication\\WindowsFormsApplication\\Database1.sdf;");
            myConnection.Open();
            SqlCeCommand myCommand = myConnection.CreateCommand();
            myCommand.CommandText = "INSERT INTO [mytable] ([name], [email]) VALUES  " + " ('" + this.txtName.Text + "','" + this.txtEmail.Text + "' ) ";
            myCommand.CommandType = CommandType.Text;
            myCommand.ExecuteNonQuery();
            myConnection.Close();

                //*** Insert to Database ***'
                SqlConnection objConn = new SqlConnection();
                string strConnString = null;
                string strSQL = null;

                strConnString = "Server=localhost;UID=sa;PASSWORD=;database=mydatabase;Max Pool Size=400;Connect Timeout=600;";

                strSQL = "INSERT INTO files (Name,FilesName,FilesType) VALUES (@sName,@sFilesName,@sFilesType)";
                objConn.ConnectionString = strConnString;
                objConn.Open();

                SqlCommand objCmd = new SqlCommand(strSQL, objConn);
				objCmd.Parameters.Add("@sName", SqlDbType.Binary).Value = this.txtName.Text;
				objCmd.Parameters.Add("@sFilesName", SqlDbType.VarChar).Value = imbByte;
				objCmd.Parameters.Add("@sFilesType", SqlDbType.Int).Value = strMIME;
                objCmd.ExecuteNonQuery();

                objConn.Close();
                objConn = null;

   sb.Remove(0, sb.Length);
   sb.Append("insert into ตารางที่จะบันทึก(ID,FirsName,LastName)values('"+@ID+"','"+@FirsName+"','"+@LastName+"')");
   string saveBat = sb.ToString();
   com = new SqlCommand();
   com.CommandType = CommandType.Text;
   com.CommandText = saveBat;
   com.Connection = con;
    com.ExecuteNonQuery();

 SqlConnection objConn = new SqlConnection();
            string strConnString = null;
            string strsql = null;
            strConnString = "Server =NOOMYONT-682684;UID=;Password=;database=SchoolSQL;Max Pool Size=400;Connect Timeout=600;";
            strsql = "INSERT INTO  SchoolSQL(ID,Fname,Sname) VALUES(@txtID,@txtFname,@Sname)";
            objConn.ConnectionString = strConnString;
            objConn.Open();

            SqlCommand objcmd = new SqlCommand(strsql, objConn);
            objcmd.Parameters.Add("@ID", SqlDbType.Binary).Value = this.txtID.Text;
            objcmd.Parameters.Add("@txtFname",SqlDbType.VarChar).Value = this.txtFname.Text;
            objcmd.Parameters.Add("@txtSname", SqlDbType.VarChar).Value = this.txtLname.Text;
            objcmd.ExecuteNonQuery();
            objConn.Close();
            objConn = null;

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace DataEntry
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        SqlConnection Conn;
        SqlCommand com;
        SqlDataReader dr;
        StringBuilder sb = new StringBuilder();
        private void Form2_Load(object sender, EventArgs e)
        {
            string strConn;
            strConn = "Data Source=.\\SQLExpress;Initial Catalog=Northwind;Integrated Security=True";
            Conn = new SqlConnection();
            if (Conn.State == ConnectionState.Open)
            {
                Conn.Close();
            }
            Conn.ConnectionString = strConn;
            Conn.Open();
        }

        private void button1_Click(object sender, EventArgs e)
        {

            if (textBox1.Text.Trim() == "")
            {
                MessageBox.Show("กรุณาป้อนรหัสลูกค้า !!!", "ข้อผิดพลาด", MessageBoxButtons.OK, MessageBoxIcon.Exclamation );
                textBox1.Focus();
                return;
            }
            sb.Remove(0, sb.Length);
            sb.Append("INSERT INTO SchoolSQL(ID,Fname,Sname)VALUES(@txtID,@txtFname,@Sname)");
            sb.Append(" VALUES (@CustomerID,@OrderDate)");
            string sqlSave = sb.ToString();
            com.CommandType = CommandType.Text;
            com.CommandText = sqlSave;
            com.Connection = Conn;

            com.Parameters.Clear();
            com.Parameters.Add("@txtID", SqlDbType.NChar).Value = textBox1.Text.Trim();
            com.Parameters.Add("@txtFname", SqlDbType.NChar).Value = textBox2.Text.Trim();
            com.Parameters.Add("@Sname", SqlDbType.NChar).Value = textBox3.Text.Trim();
            com.ExecuteNonQuery();
            MessageBox.Show("บันทึกข้อมูลเรียบร้อยแล้ว", "รายงานผล", MessageBoxButtons.OK, MessageBoxIcon.Information);

        }
    }
}

SqlConnection conn; 



StringBuilder sb = new StringBuilder();


SqlConnection Conn = new SqlConnection ("Data Source=./SQLEXPRESS; Initial Catalog=lam; Integrated Security=True");


private void Form1_Load(object sender, EventArgs e)
{

if (conn.State == ConnectionState.Open)
{

conn.Close();

}

}

private void button2_Click(object sender, EventArgs e)
{

if (tetID.Text.Trim() == "")

{

MessageBox.Show("กรุณาป้อนรหัสลูกค้า !!!", "ข้อผิดพลาด", MessageBoxButtons.OK, MessageBoxIcon.Exclamation );

tetID.Focus();

return;

}

try

{

conn.Open();

string sql = "INSERT INTO lam (ID,name,lastname)VALUES(@tetID,@tetname,@tetlastname)";

SqlCommand cmd = new SqlCommand(sql, conn);

string texID = tetID.Text.Trim();

string texName = tetname.Text.Trim();

string texlastName = tetlastname.Text.Trim();

cmd.Parameters.Add(new SqlParameter("@tetID", tetID));

cmd.Parameters.Add(new SqlParameter("@tetname", tetname));

cmd.Parameters.Add(new SqlParameter("@tetlastname", tetlastname));

SqlDataReader reader = cmd.ExecuteReader();

MessageBox.Show("บันทึกข้อมูลเรียบร้อยแล้ว", "รายงานผล", MessageBoxButtons.OK, MessageBoxIcon.Information);

Conn.Close();

}

catch

{

MessageBox.Show ("Error");

}

}
}
}