c#.net连接access操作类（转）

1、配置web.config文件：配置数据库连接参数

<configuration>
<appSettings/>
<connectionStrings>
  <add name="ConnectionString" connectionString="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=F:\TeacherSystem\App_Data\db.mdb;Jet OLEDB:Database Password=123"
   providerName="System.Data.OleDb" />
</connectionStrings>

2
程序设计开始：

1、按要求建立Access数据库及数据表

2、编写数据库访问、操作的公用类，此类可以复用到以后开发的任何系统中

（1）、新建一个C# 类库项目， 命名为“Com.LXJ”，设置项目属性：程序集名称、默认命名空间均为“Com.LXJ”

（2）、在此项目目录下创建目录Database，新建C# 类文件ConnDbForAccess.cs 在Database目录下。

              添加引用：System.Web.dll

（3）、编写ConnDbForAccess.cs 的代码

  using System;
using System.Data;
using System.Data.OleDb;
using System.Web;
using System.Web.UI;
using System.Configuration;

namespace Com.LXJ.Database
{
    /// <summary>
    /// conn 的摘要说明。
    /// </summary>
    public class ConnDbForAcccess
    {
        /// <summary>
        /// 连接数据库字符串
        /// </summary>
        private string connectionString;

        /// <summary>
        /// 存储数据库连接（保护类，只有由它派生的类才能访问）
        /// </summary>
        protected OleDbConnection Connection;

        /// <summary>
        /// 构造函数：数据库的默认连接
        /// </summary>
        public ConnDbForAcccess()
        {
            string connStr;
            connStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString.ToString();
           // connStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString(); //从web.config配置中读取
            connectionString = connStr;
            //connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Request.PhysicalApplicationPath + connStr;
           // connectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString();
            //
            Connection = new OleDbConnection(connectionString);
        }

        /// <summary>
        /// 构造函数：带有参数的数据库连接
        /// </summary>
        /// <param name="newConnectionString"></param>
        public ConnDbForAcccess(string newConnectionString)
        {
            //connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Request.PhysicalApplicationPath + newConnectionString;
            connectionString = newConnectionString;
            Connection = new OleDbConnection(connectionString);
        }

        /// <summary>
        /// 获得连接字符串
        /// </summary>
        public string ConnectionString
        {
            get
            {
                return connectionString;
            }
        }

        /// <summary>
        /// 执行SQL语句没有返回结果，如：执行删除、更新、插入等操作
        /// </summary>
        /// <param name="strSQL"></param>
        /// <returns>操作成功标志</returns>
        public bool ExeSQL(string strSQL)
        {
            bool resultState = false;

            Connection.Open();
            OleDbTransaction myTrans = Connection.BeginTransaction();
            OleDbCommand command = new OleDbCommand(strSQL, Connection, myTrans);

            try
            {
                command.ExecuteNonQuery();
                myTrans.Commit();
                resultState = true;
            }
            catch
            {
                myTrans.Rollback();
                resultState = false;
            }
            finally
            {
                Connection.Close();
            }
            return resultState;
        }

        /// <summary>
        /// 执行SQL语句返回结果到DataReader中
        /// </summary>
        /// <param name="strSQL"></param>
        /// <returns>dataReader</returns>
        private OleDbDataReader ReturnDataReader(string strSQL)
        {
            Connection.Open();
            OleDbCommand command = new OleDbCommand(strSQL, Connection);
            OleDbDataReader dataReader = command.ExecuteReader();
            Connection.Close();

            return dataReader;
        }

        /// <summary>
        /// 执行SQL语句返回结果到DataSet中
        /// </summary>
        /// <param name="strSQL"></param>
        /// <returns>DataSet</returns>
        public DataSet ReturnDataSet(string strSQL)
        {
            Connection.Open();
            DataSet dataSet = new DataSet();
            OleDbDataAdapter OleDbDA = new OleDbDataAdapter(strSQL, Connection);
            OleDbDA.Fill(dataSet, "objDataSet");

            Connection.Close();
            return dataSet;
        }

        /// <summary>
        /// 执行一查询语句，同时返回查询结果数目
        /// </summary>
        /// <param name="strSQL"></param>
        /// <returns>sqlResultCount</returns>
        public int ReturnSqlResultCount(string strSQL)
        {
            int sqlResultCount = 0;

            try
            {
                Connection.Open();
                OleDbCommand command = new OleDbCommand(strSQL, Connection);
                OleDbDataReader dataReader = command.ExecuteReader();

                while (dataReader.Read())
                {
                    sqlResultCount++;
                }
                dataReader.Close();
            }
            catch
            {
                sqlResultCount = 0;
            }
            finally
            {
                Connection.Close();
            }
            return sqlResultCount;
        }

    }//
}//

好了，数据库访问、数据库操作的公用类完成了，详细代码意义大家自己看吧，这些属于C# 语法知识了，现在可以编译生成项目了，编译完后把项目的dll文件Com.LXJ.dll拷贝到Example项目下的bin目录中，然后在项目 Example中引入Com.LXJ.dll即可。稍后介绍如何使用它，休息一下，喝口水，呵呵.....