C#操作Access数据库

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.OleDb;
using System.Configuration;

namespace DBHelper
{
class DBHelperAccess
{

#region 变量声明处
public OleDbConnection Conn;
public string ConnString;//连接字符串
#endregion

#region 构造函数与连接关闭数据库

public DBHelperAccess()
{
//ConnString = "Provider=Microsoft.Jet.OleDb.4.0;Data Source=";//03-07数据库用

//2010数据库以上版本
ConnString =  @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=F:\DBHelper\DBHelper\DB.accdb";

//获取程序当前路径
//string startpath = System.Windows.Forms.Application.StartupPath ;

if (Conn == null)
{
Conn = new OleDbConnection(ConnString);
}
if (Conn.State != ConnectionState.Open)
{
Conn.Open();
}

}

/// <summary>
/// 构造函数
/// </summary>
/// <param name="DbName">ACCESS数据库名称</param>
public DBHelperAccess(string DbName)
{
ConnString = "Provider=Microsoft.Jet.OleDb.4.0;Data Source=";
ConnString += System.Windows.Forms.Application.StartupPath + "\\" + DbName;
if (Conn == null)
{
Conn = new OleDbConnection(ConnString);
}
if (Conn.State != ConnectionState.Open)
{
Conn.Open();
}
}

/// </summary>
/// 打开数据源链接
/// </summary>
/// <returns></returns>
public OleDbConnection DbConn()
{
Conn.Open();
return Conn;
}

/// </summary>
/// 请在数据传递完毕后调用该函数，关闭数据链接。
/// </summary>
public void Close()
{
Conn.Close();
}
#endregion

#region 数据库基本操作

/// <summary>
/// 根据SQL命令返回数据DataTable数据表,
/// 可直接作为dataGridView的数据源
/// </summary>
/// <param name="SQL"></param>
/// <returns></returns>
public DataTable SelectToDataTable(string SQL)
{
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand(SQL, Conn);
adapter.SelectCommand = command;
DataTable Dt = new DataTable();
adapter.Fill(Dt);
return Dt;
}

/// <summary>
/// 根据SQL命令返回数据DataSet数据集
/// </summary>
/// <param name="SQL"></param>
/// <param name="subtableName">在返回的数据集中所添加的表的名称</param>
/// <returns></returns>
public DataSet SelectToDataSet(string SQL, string subtableName)
{
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand(SQL, Conn);
adapter.SelectCommand = command;
DataSet Ds = new DataSet();
Ds.Tables.Add(subtableName);
adapter.Fill(Ds, subtableName);
return Ds;
}

/// <summary>
/// 在指定的数据集中添加带有指定名称的表，由于存在覆盖已有名称表的危险，返回操作之前的数据集。
/// </summary>
/// <param name="SQL"></param>
/// <param name="subtableName">添加的表名</param>
/// <param name="DataSetName">被添加的数据集名</param>
/// <returns></returns>
public DataSet SelectToDataSet(string SQL, string subtableName, DataSet DataSetName)
{
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand(SQL, Conn);
adapter.SelectCommand = command;
DataTable Dt = new DataTable();
DataSet Ds = new DataSet();
Ds = DataSetName;
adapter.Fill(DataSetName, subtableName);
return Ds;
}

/// <summary>
/// 根据SQL命令返回OleDbDataAdapter，
/// 使用前请在主程序中添加命名空间System.Data.OleDb
/// </summary>
/// <param name="SQL"></param>
/// <returns></returns>
public OleDbDataAdapter SelectToOleDbDataAdapter(string SQL)
{
OleDbDataAdapter adapter = new OleDbDataAdapter();
OleDbCommand command = new OleDbCommand(SQL, Conn);
adapter.SelectCommand = command;
return adapter;
}

/// <summary>
/// 执行SQL命令，不需要返回数据的修改，删除可以使用本函数
/// </summary>
/// <param name="SQL"></param>
/// <returns></returns>
public bool ExecuteSQLNonquery(string SQL)
{
OleDbCommand cmd = new OleDbCommand(SQL, Conn);
try
{
cmd.ExecuteNonQuery();
return true;
}
catch
{
return false;
}
}
#endregion
}
}

DBHelperAccess db = new DBHelperAccess();

dataGridView1.DataSource = db.SelectToDataTable("select * from 用户");

db.Close();