ADO.NET and Oracle (VB.NET/C#) เขียนโปรแกรมติดต่อกับฐานข้อมูล Oracle Database

create table MEMBER
(
  CUSTOMERID  VARCHAR2(4),
  USERNAME    VARCHAR2(30),
  PASSWORD    VARCHAR2(30),
  NAME        VARCHAR2(50),
  EMAIL       VARCHAR2(50),
  COUNTRYCODE VARCHAR2(2),
  BUDGET      NUMBER,
  USED        NUMBER
)

-- Data

insert into MEMBER (CUSTOMERID, USERNAME, PASSWORD, NAME, EMAIL, COUNTRYCODE, BUDGET, USED)
values ('C001', 'win', 'win123', 'Win Weerachai', '[email protected]', 'TH', 1000000, 600000);
insert into MEMBER (CUSTOMERID, USERNAME, PASSWORD, NAME, EMAIL, COUNTRYCODE, BUDGET, USED)
values ('C002', 'john', 'john123', 'John  Smith', '[email protected]', 'EN', 2000000, 800000);
insert into MEMBER (CUSTOMERID, USERNAME, PASSWORD, NAME, EMAIL, COUNTRYCODE, BUDGET, USED)
values ('C003', 'jame', 'jame123', 'Jame Born', '[email protected]', 'US', 3000000, 600000);
insert into MEMBER (CUSTOMERID, USERNAME, PASSWORD, NAME, EMAIL, COUNTRYCODE, BUDGET, USED)
values ('C004', 'chalee', 'chalee123', 'Chalee Angel', '[email protected]', 'US', 4000000, 100000);

Imports System.Data.OracleClient
Imports System.Data
Public Class frmLogin

    Private Sub btnLogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogin.Click

        Dim objConn As New OracleConnection
        Dim objCmd As New OracleCommand
        Dim strConnString, strSQL As String

        strConnString = "Data Source=TCDB;User Id=myuser;Password=mypassword;"
        objConn.ConnectionString = strConnString
        objConn.Open()

        Dim intNumRows As Integer
        strSQL = "SELECT COUNT(*) FROM MEMBER WHERE USERNAME = '" & Me.txtUsername.Text & "' AND PASSWORD = '" & Me.txtPassword.Text & "' "
        objCmd = New OracleCommand(strSQL, objConn)
        intNumRows = objCmd.ExecuteScalar()

        If intNumRows > 0 Then
            Dim frm As New frmMain
            frm._strUser = Me.txtUsername.Text
            frm.LoadInfor()
            frm.Show()

            Me.Hide()
        Else
            MessageBox.Show("Username or Password Incorrect")
        End If

        objConn.Close()
        objConn = Nothing

    End Sub

    Private Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click
        If MessageBox.Show("Exit application?", "", MessageBoxButtons.YesNo) = DialogResult.Yes Then
            Application.Exit()
        End If
    End Sub


End Class

Imports System.Data.OracleClient
Imports System.Data

Public Class frmMain

    Dim strUser As String

    Public Property _strUser() As String
        Get
            Return strUser
        End Get
        Set(ByVal value As String)
            strUser = value
        End Set
    End Property

    Public Sub LoadInfor()

        Dim objConn As New OracleConnection
        Dim objCmd As New OracleCommand
        Dim dtAdapter As OracleDataAdapter
        Dim dt As New DataTable
        Dim strConnString, strSQL As String

        strConnString = "Data Source=TCDB;User Id=myuser;Password=mypassword;"
        objConn.ConnectionString = strConnString
        objConn.Open()

        strSQL = "SELECT * FROM MEMBER WHERE USERNAME = '" & strUser & "' "

        dtAdapter = New OracleDataAdapter(strSQL, objConn)
        dtAdapter.Fill(dt)

        If dt.Rows.Count > 0 Then
            Me.lblUser.Text = strUser
            Me.lblName.Text = dt.Rows(0)("NAME")
            Me.lblEmail.Text = dt.Rows(0)("EMAIL")
        End If

        objConn.Close()
        objConn = Nothing
    End Sub

    Private Sub btnBack_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBack.Click
        Dim frm As New frmLogin
        frm.Show()

        Me.Hide()
    End Sub
End Class

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.OracleClient;
using System.IO;

namespace LoginFormCS
{
    public partial class frmLogin : Form
    {
        public frmLogin()
        {
            InitializeComponent();
        }

        private void btnLogin_Click(object sender, EventArgs e)
        {
            OracleConnection objConn = new OracleConnection();
            OracleCommand objCmd = new OracleCommand();
            string strConnString = null;
            string strSQL = null;

            strConnString = "Data Source=TCDB;User Id=myuser;Password=mypassword;";
            objConn.ConnectionString = strConnString;
            objConn.Open();

            int intNumRows = 0;
            strSQL = "SELECT COUNT(*) FROM MEMBER WHERE USERNAME = '" + this.txtUsername.Text + "' AND PASSWORD = '" + this.txtPassword.Text + "' ";
            objCmd = new OracleCommand(strSQL, objConn);
            intNumRows = Convert.ToInt32(objCmd.ExecuteScalar());

            if (intNumRows > 0)
            {
                frmMain frm = new frmMain();
                frm._strUser = this.txtUsername.Text;
                frm.LoadInfor();
                frm.Show();

                this.Hide();
            }
            else
            {
                MessageBox.Show("Username or Password Incorrect");
            }

            objConn.Close();
            objConn = null;
        }

        private void btnClose_Click(object sender, EventArgs e)
        {
            if (MessageBox.Show("Exit application?", "", MessageBoxButtons.YesNo) == DialogResult.Yes)
            {
                Application.Exit();
            }
        }


    }
}

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.OracleClient;
using System.IO;

namespace LoginFormCS
{


    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }

        string strUser;
        public string _strUser
        {
            get { return strUser; }
            set { strUser = value; }
        }

        public void LoadInfor()
        {
            OracleConnection objConn = new OracleConnection();
            OracleCommand objCmd = new OracleCommand();
            OracleDataAdapter dtAdapter = default(OracleDataAdapter);
            DataTable dt = new DataTable();
            string strConnString = null;
            string strSQL = null;

            strConnString = "Data Source=TCDB;User Id=myuser;Password=mypassword;";
            objConn.ConnectionString = strConnString;
            objConn.Open();

            strSQL = "SELECT * FROM MEMBER WHERE USERNAME = '" + strUser + "' ";

            dtAdapter = new OracleDataAdapter(strSQL, objConn);
            dtAdapter.Fill(dt);

            if (dt.Rows.Count > 0)
            {
                this.lblUser.Text = strUser;
                this.lblName.Text = dt.Rows[0]["NAME"].ToString();
                this.lblEmail.Text = dt.Rows[0]["EMAIL"].ToString();
            }

            objConn.Close();
            objConn = null;
        }

        private void btnBack_Click(object sender, EventArgs e)
        {
        frmLogin frm = new frmLogin();
        frm.Show();
        this.Hide();
        }
    }
}