using System;
using System.Data;
using System.Data.OleDb;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
namespace AccessDBHelper
... {
/// <summary>
/// 封装Access数据库的常用操作。
/// 覃雁禄 [email protected] 2007-11-21
/// </summary>
public sealed class DBHelper
...{
private static string connectionString = null;
private static OleDbConnection connection = null;
/// <summary>
/// 返回当前的数据库连接对象OleDbConnection。
/// </summary>
public static OleDbConnection Connection
...{
get ...{ return connection; }
}
static DBHelper()
...{
//数据库路径存储在web.config
connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source="
+ HttpContext.Current.Server.MapPath(ConfigurationSettings.AppSettings["DataPath"]);
}
/// <summary>
/// 创建一个OleDbCommand对象实例
/// </summary>
/// <param name="commandText">SQL命令</param>
/// <param name="connection">数据库连接对象实例OleDbConnection</param>
/// <param name="oleDbParameters">可选参数</param>
/// <returns></returns>
private static OleDbCommand CreateCommand(string commandText, OleDbConnection connection,
params System.Data.OleDb.OleDbParameter[] oleDbParameters)
...{
if (connection == null)
connection = new OleDbConnection(connectionString);
if (connection.State == ConnectionState.Closed)
connection.Open();
OleDbCommand comm = new OleDbCommand(commandText, connection);
if (oleDbParameters != null)
...{
foreach (OleDbParameter parm in oleDbParameters)
...{
comm.Parameters.Add(parm);
}
}
return comm;
}
/// <summary>
/// 创建一个OleDbParameter参数对象实例
/// </summary>
/// <param name="parmname">参数名称</param>
/// <param name="parmvalue">参数值</param>
/// <returns></returns>
public static OleDbParameter MakeParm(string parmname, object parmvalue)
...{
return new OleDbParameter(parmname, parmvalue);
}
/// <summary>
/// 执行 SQL INSERT、DELETE、UPDATE 和 SET 语句等命令。
/// </summary>
/// <param name="commandText">SQL命令</param>
/// <param name="oleDbParameters">可选参数</param>
/// <returns></returns>
public static int ExecuteNonQuery(string commandText, params System.Data.OleDb.OleDbParameter[] oleDbParameters)
...{
OleDbCommand comm = CreateCommand(commandText, connection, oleDbParameters);
return comm.ExecuteNonQuery();
}
/// <summary>
/// 从数据库中检索单个值(例如一个聚合值)。
/// </summary>
/// <param name="commandText"></param>
/// <param name="oleDbParameters"></param>
/// <returns></returns>
public static object ExecuteScalar(string commandText, params System.Data.OleDb.OleDbParameter[] oleDbParameters)
...{
OleDbCommand comm = CreateCommand(commandText, connection, oleDbParameters);
return comm.ExecuteScalar();
}
/// <summary>
/// 提供读取数据行的方法。
/// </summary>
/// <param name="commandText">SQL命令</param>
/// <param name="oleDbParameters">可选参数</param>
/// <returns>OleDbDataReader</returns>
public static OleDbDataReader ExecuteDataReader(string commandText, params System.Data.OleDb.OleDbParameter[] oleDbParameters)
...{
OleDbCommand comm = CreateCommand(commandText, connection, oleDbParameters);
return comm.ExecuteReader();
}
/// <summary>
/// 表示一组数据命令和一个数据库连接，它们用于填充 DataSet 和更新数据源。
/// </summary>
/// <param name="commandText">SQL命令</param>
/// <param name="oleDbParameters">可选参数</param>
/// <returns></returns>
public static OleDbDataAdapter ExecuteDataAdapter(string commandText, params System.Data.OleDb.OleDbParameter[] oleDbParameters)
...{
OleDbCommand comm = CreateCommand(commandText, connection, oleDbParameters);
OleDbDataAdapter da = new OleDbDataAdapter(comm);
OleDbCommandBuilder cb = new OleDbCommandBuilder(da);
return da;
}
/// <summary>
/// 返回一个DataSet数据集。
/// </summary>
/// <param name="commandText">SQL命令</param>
/// <param name="oleDbParameters">可选参数</param>
/// <returns>DataSet</returns>
public static DataSet ExecuteDataSet(string commandText, params OleDbParameter[] oleDbParameters)
...{
DataSet ds = new DataSet();
OleDbCommand comm = CreateCommand(commandText, connection, oleDbParameters);
OleDbDataAdapter da = new OleDbDataAdapter(comm);
da.Fill(ds);
return ds;
}
}
}