dbhelper.cs

我们刚刚学的内容,挺有用的,希望大家指导一下,我很高兴能将我的资源在此共享

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;


/// <summary>
/// Summary description for DBHelper
/// </summary>
public class DBHelper

{
    //Properties.Settings.Default.connstr

    public static SqlConnection conn = new SqlConnection( "server=.;database=bookdb;integrated security=true");
  
	public DBHelper()
	{
		//
		// TODO: Add constructor logic here
		//
	}

    	
		//执行查询，返回DataSet对象(多条记录)
		public  static  DataSet executeQueryDs(string sql)
		{
            		
		SqlDataAdapter da;
		DataSet ds;		
			da=new SqlDataAdapter(sql,conn);		
			ds=new DataSet();
			da.Fill(ds);		
			return ds;
		}
		//执行查询，返回SqlDataReader对象(一条记录)
		public  static  SqlDataReader executeQueryDr(string sql)
		{
            SqlDataReader dr;
	 SqlCommand cmd;
			cmd=new SqlCommand(sql,conn);
            openConn();
			dr=cmd.ExecuteReader(CommandBehavior.CloseConnection);
			return dr;
		}
		//执行更新，返回所影响的行数
		public  static  bool executeUpdate(string strUpdate)
		{
      
	SqlCommand cmd;

				cmd=new SqlCommand(strUpdate,conn);
                openConn();
				int rows;
				rows=cmd.ExecuteNonQuery();
				conn.Close();
				if(rows>0)
				{
					return true;
				}
				else
				{ 
					return false;
				}
		

		}

    static void openConn()
    {
        if (conn.State == ConnectionState.Closed)
        {
            conn.Open();
        }
    }

    static void close()
    {
        if (conn.State==ConnectionState.Open)
        {
            conn.Close();
        }
    }


	}