C# 对Access数据库操作的通用类

(转载自博主Jerry很简单）

//Access数据库-C# 操作类 代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.OleDb;
using System.Data;

namespace XXX
{
    class AccessHelper
    {

private string conn_str = null;
private OleDbConnection ole_connection = null;
private OleDbCommand ole_command = null;
private OleDbDataReader ole_reader = null;
private DataTable dt = null;

/// <summary>
/// 构造函数
/// </summary>
public AccessHelper()
{
conn_str =@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source='D:\我的文档\Visual Studio 2008\Projects\AccessOperator\AccessOperator\bin\Debug\myDb.mdb'";
InitDB();
}

private void InitDB()
{
ole_connection =new OleDbConnection(conn_str);//创建实例
ole_command =new OleDbCommand();
}

/// <summary>
/// 构造函数
/// </summary>
/// <param name="db_path">数据库路径</param>
public AccessHelper(string db_path)
{
conn_str ="Provider=Microsoft.Jet.OLEDB.4.0;Data Source='"+ db_path + "'";
InitDB();
}

/// <summary>
/// 转换数据格式
/// </summary>
/// <param name="reader">数据源</param>
/// <returns>数据列表</returns>
private DataTable ConvertOleDbReaderToDataTable(ref OleDbDataReader reader)
{
DataTable dt_tmp =null;
DataRow dr =null;
int data_column_count = 0;
int i = 0;

data_column_count = reader.FieldCount;
dt_tmp = BuildAndInitDataTable(data_column_count);

if(dt_tmp == null)
{
return null;
}

while(reader.Read())
{
dr = dt_tmp.NewRow();

for(i = 0; i < data_column_count; ++i)
{
dr[i] = reader[i];
}

dt_tmp.Rows.Add(dr);
}

return dt_tmp;
}

/// <summary>
/// 创建并初始化数据列表
/// </summary>
/// <param name="Field_Count">列的个数</param>
/// <returns>数据列表</returns>
private DataTable BuildAndInitDataTable(int Field_Count)
{
DataTable dt_tmp =null;
DataColumn dc =null;
int i = 0;

if(Field_Count <= 0)
{
return null;
}

dt_tmp =new DataTable();

for(i = 0; i < Field_Count; ++i)
{
dc =new DataColumn(i.ToString());
dt_tmp.Columns.Add(dc);
}

return dt_tmp;
}

/// <summary>
/// 从数据库里面获取数据
/// </summary>
/// <param name="strSql">查询语句</param>
/// <returns>数据列表</returns>
public DataTable GetDataTableFromDB(string strSql)
{
if(conn_str == null)
{
return null;
}

try
{
ole_connection.Open();//打开连接

if(ole_connection.State == ConnectionState.Closed)
{
return null;
}

ole_command.CommandText = strSql;
ole_command.Connection = ole_connection;

ole_reader = ole_command.ExecuteReader(CommandBehavior.Default);

dt = ConvertOleDbReaderToDataTable(ref ole_reader);

ole_reader.Close();
ole_reader.Dispose();
}
catch(System.Exception e)
{
Console.WriteLine(e.ToString());
}
finally
{
if(ole_connection.State != ConnectionState.Closed)
{
ole_connection.Close();
}
}

return dt;
}

/// <summary>
/// 执行sql语句
/// </summary>
/// <param name="strSql">sql语句</param>
/// <returns>返回结果</returns>
public int ExcuteSql(string strSql)
{
int nResult = 0;

try
{
ole_connection.Open();//打开数据库连接
if(ole_connection.State == ConnectionState.Closed)
{
return nResult;
}

ole_command.Connection = ole_connection;
ole_command.CommandText = strSql;

nResult = ole_command.ExecuteNonQuery();
}
catch(System.Exception e)
{
Console.WriteLine(e.ToString());
return nResult;
}
finally
{
if(ole_connection.State != ConnectionState.Closed)
{
ole_connection.Close();
}
}

return nResult;
}

//static void Main(string[] args)
//{
// AccessHelper Helper =new AccessHelper();
// DataTable dt = Helper.GetDataTableFromDB("select * from test");

// foreach(DataRow dr in dt.Rows)
// {
// Console.WriteLine(dr[0].ToString()+" "+dr[1].ToString());
// }

// Console.WriteLine(Helper.ExcuteSql("insert into test(test) values ('hello')"));
//}

}
}