form1.cs

CSharp2005从入门到精通电子书含习题

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.OracleClient;

namespace UserDemo
{
    public partial class FrmUserDemo : Form
    {
        string ConnectionString = "Data Source=seaexpress;Persist Security Info=True;User ID=se;Password=sea;Unicode=True";
        string QueryString = "SELECT CODE,FIRSTNAME,LASTNAME,EMAILADDRESS FROM USER";
        DataSet dsUser;
        public FrmUserDemo()
        {
            InitializeComponent();
            dsUser = null;
           
        }

        private void btnSearch_Click(object sender, EventArgs e)
        {
            dsUser = QueryUser();
            bsUser.DataSource = dsUser.Tables["USER"];
            this.dataGridView1.DataSource = bsUser;
        }

        private DataSet QueryUser()
        {
            OracleConnection myConnction = new OracleConnection(ConnectionString);
            OracleCommand myCommand = myConnction.CreateCommand();
            myCommand.CommandText = QueryString;
            OracleDataAdapter myAdapter = new OracleDataAdapter();
            myAdapter.SelectCommand = myCommand;
            DataSet myDataSet = new DataSet();
            myConnction.Open();
            myAdapter.Fill(myDataSet, "USER");
            myConnction.Close();
            return myDataSet;
        }

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

        private void btnReset_Click(object sender, EventArgs e)
        {
            dsUser = null;
            bsUser.DataSource = null;
            
            this.dataGridView1.Refresh();
        }
    }
}