using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace MyGz530AccessHelp
{using System.Data;using System.Data.OleDb;public class Gz530AccessHelp{// 连接数据源private OleDbConnection conn = null;/// <summary>/// 数据源/// </summary>/// <param name="conStr">数据源连接字符串</param>public OleDbConnection DataBase(string conStr){conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+ conStr +";Jet OLEDB:System Database=system.mdw;");this.Open();return conn;}/// <summary>/// 根据SQL查询返回DataSet对象，如果没有查询到则返回NULL/// </summary>/// <param name="sql">查询语句</param>/// <returns>DataSet</returns>public DataSet GetDataSet(string sql){DataSet ds = new DataSet();try{OleDbCommand cmd = new OleDbCommand(sql, conn);cmd.CommandTimeout = 20;System.Data.OleDb.OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);adapter.Fill(ds, "tempTable");}catch (Exception e){ds = null;}return ds;}/// <summary>/// 根据SQL查询返回DataSet对象，如果没有查询到则返回NULL/// </summary>/// <param name="sql">查询语句</param>/// <param name="sRecord">开始记录数</param>/// <param name="mRecord">最大记录数</param>/// <returns>DataSet</returns>public DataSet GetDataSet(string sql, int sRecord, int mRecord){DataSet ds = new DataSet();try{OleDbCommand cmd = new OleDbCommand(sql, conn);cmd.CommandTimeout = 20;System.Data.OleDb.OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);adapter.Fill(ds, sRecord, mRecord, "tempTable");}catch (Exception e){ds = null;}return ds;}/// <summary>/// 对数据库的增，删，改的操作/// </summary>/// <param name="sql">SQL语句</param>/// <returns>是否成功</returns>public bool ExecuteDataBase(string sql){bool succeed = false;int cnt = 0;try{OleDbCommand cmd = new OleDbCommand(sql, conn);cmd.CommandTimeout = 20;if (this.Open())cnt = cmd.ExecuteNonQuery();}catch (Exception e){e.ToString();}finally{if (cnt > 0){succeed = true;}}return succeed;}/// <summary>/// 获得该SQL查询返回的第一行第一列的值，如果没有查询到则返回NULL/// </summary>/// <param name="sql">查询语句</param>/// <returns>返回的第一行第一列的值</returns>public string GetScalar(string sql){string str = null;try{OleDbCommand cmd = new OleDbCommand(sql, conn);if (this.Open())str = cmd.ExecuteScalar().ToString();}catch (Exception e){e.ToString();}return str;}/// <summary>///  获得该SQL查询返回DataTable，如果没有查询到则返回NULL/// </summary>/// <param name="sql">查询语句</param>/// <returns></returns>public DataTable GetDataTable(string sql){DataTable tb = null;DataSet ds = this.GetDataSet(sql);if (ds != null){tb = ds.Tables["tempTable"];}return tb;}/// <summary>/// 打开数据库连接./// </summary>private bool Open(){bool succeed = false;try{if (conn.State == System.Data.ConnectionState.Closed){conn.Open();succeed = true;}else if (conn.State == System.Data.ConnectionState.Broken){conn.Close();conn.Open();succeed = true;}else if (conn.State == System.Data.ConnectionState.Open){succeed = true;}}catch (Exception e){e.ToString();}return succeed;}/// <summary>/// 关闭数据库连接/// </summary>public void Close(){if (conn != null){conn.Close();}}/// <summary>/// 释放数据库连接资源/// </summary>public void Dispose(){if (conn != null){conn.Dispose();conn = null;}}}}