求C#的WINFORM MSSQL数据库操作实例，在线等

Question

为本人刚学数C#,现在求一个数据库C#的WINFORM数据库操作类,并含一个使用例子,谢谢.最好能简单讲解一下.

Answer 1

20分？？？using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;namespace WindowsFormsApplication5
{
    public class DBHelper
    {
        //string strAppConfigFile = ConfigurationManager.AppSettings["DataBaseType"].ToString();        //Helper _helper = new Helper();
        //public  Helper GetHelper()
        //{            
        //    switch (strAppConfigFile)
        //    {
        //        case "System.Data.OracleClient":
        //            _helper.DatabaseType = Helper.DatabaseTypes.Oracle;
        //            break;
        //        case "MySql.Data.MySqlClient":
        //            _helper.DatabaseType = Helper.DatabaseTypes.MySql;
        //            break;
        //        case "System.Data.OleDb":
        //            _helper.DatabaseType = Helper.DatabaseTypes.OleDb;
        //            break;
        //        case "System.Data.SqlClient":
        //        default:
        //            _helper.DatabaseType = Helper.DatabaseTypes.Sql;
        //            break;
        //    }
        //    return _helper;        //}
        private static SqlConnection connection;
        public static SqlConnection Connection
        {
            get
            {
                string connectionString = "server=MMIT017\\SQL2008;database=TestDB;uid=sa;pwd=123456";
                if (connection == null)
                {
                    connection = new SqlConnection(connectionString);
                    connection.Open();
                }
                else if (connection.State == System.Data.ConnectionState.Closed)
                {
                    connection.Open();
                }
                else if (connection.State == System.Data.ConnectionState.Broken)
                {
                    connection.Close();
                    connection.Open();
                }
                return connection;
            }
        }        public static int ExecuteCommand(string safeSql)
        {
            SqlCommand cmd = new SqlCommand(safeSql, Connection);
            int result = cmd.ExecuteNonQuery();
            return result;
        }        public static int ExecuteCommand(string sql, params SqlParameter[] values)
        {
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddRange(values);
            return cmd.ExecuteNonQuery();
        }        public static int ExecuteCommand2(string sql, params SqlParameter[] values)
        {
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.Parameters.AddRange(values);
            return cmd.ExecuteNonQuery();
        }        public static string GetScalar(string safeSql)
        {
            SqlCommand cmd = new SqlCommand(safeSql, Connection);
            string result = cmd.ExecuteScalar().ToString();
            return result;
        }        public string GetScalar(string sql, params SqlParameter[] values)
        {
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddRange(values);
            string result = cmd.ExecuteScalar().ToString();
            return result;
        }        public static SqlDataReader GetReader(string safeSql)
        {
            SqlCommand cmd = new SqlCommand(safeSql, Connection);
            SqlDataReader reader = cmd.ExecuteReader();
            return reader;
        }        public static SqlDataReader GetReader(string sql, params SqlParameter[] values)
        {
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddRange(values);
            SqlDataReader reader = cmd.ExecuteReader();
            return reader;
        }        public static DataTable GetDataSet(string safeSql)
        {
            DataSet ds = new DataSet();
            SqlCommand cmd = new SqlCommand(safeSql, Connection);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
            return ds.Tables[0];
        }        public static DataTable GetDataSet(string sql, params SqlParameter[] values)
        {
            DataSet ds = new DataSet();
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddRange(values);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
            return ds.Tables[0];
        }        /// <summary>
        /// 返回一个数据集，从里面取出不同的表 
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static DataSet GetDataSet3(string sql, params SqlParameter[] values)
        {
            DataSet ds = new DataSet();
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddRange(values);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
            return ds;
        }
    }
}
*****************************************************************************using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;namespace WindowsFormsApplication5
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }        private void btnADD_Click(object sender, EventArgs e)
        {
            string a = "aaa";
            string b = "bbb";
            string c = "ccc";
            string d = "ddd";
            string strSql = "insert into userinfo values('" + a + "','" + b + "','" + c + "','" + d + "',)";
            int i = DBHelper.ExecuteCommand(strSql);
            if (i > 0)
            {
                MessageBox.Show("数据增加成功");
            }
            else 
            {
                MessageBox.Show("数据增加失败");
            }
        }        private void btnDelete_Click(object sender, EventArgs e)
        {
            string UserName = "aaa";
            string strSql = "delete userinfo where username='"+UserName+"'";
            int i = DBHelper.ExecuteCommand(strSql);
            if (i > 0)
            {
                MessageBox.Show("用户删除成功");
            }
            else
            {
                MessageBox.Show("用户删除失败");
            }        }        private void btnUpdate_Click(object sender, EventArgs e)
        {
            string UserName = "aaa";
            string address = "北京市北京路1号";
            string strSql = "update userinfo set UserAddress='"+address+"' where username='" + UserName + "'";
            int i = DBHelper.ExecuteCommand(strSql);
            if (i > 0)
            {
                MessageBox.Show("用户信息更新成功");
            }
            else
            {
                MessageBox.Show("用户信息更新失败");
            }
        }        private void btnSearch_Click(object sender, EventArgs e)
        {
            string strSql = "select * from userinfo";
            DataTable dt = DBHelper.GetDataSet(strSql);
            this.dataGridView1.DataSource = dt;        }
    }
}