自用数据存取类 DataHelper.cs

using System;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
/// <summary>
/// 数据库数据存取操作类
/// 2009.3.19修改
/// 作者：小刚
/// </summary>
public class DataHelper
{
    public DataHelper(string connString)
    {
        if (connString == null)
        {
            connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["conn"].ToString();
        }
        else
            connectionString = connString;

        //初始化对象
        sqlConnection = new SqlConnection(connectionString);
        sqlCommand = new SqlCommand();

    }
    //初始化连接字符串（默认从web.config中"conn"节点读取)
    private static string connectionString;

    //数据库的连接对象
    private SqlConnection sqlConnection;

    //建立命令对象
    private SqlCommand sqlCommand;
   
    //获取DataReader对象
    public SqlDataReader GetDataReader(string strCommand, params SqlParameter[] param)
    {
        PreCommand(sqlConnection, strCommand, param);

        return sqlCommand.ExecuteReader(CommandBehavior.CloseConnection);
    }

    //获取DataSet对象
    public DataSet GetDataSet(string strCommand, params SqlParameter[] param)
    {
        PreCommand(sqlConnection, strCommand, param);

        SqlDataAdapter ad = new SqlDataAdapter(sqlCommand);

        DataSet ds = new DataSet();

        ad.Fill(ds);

        sqlConnection.Close();

        return ds;
    }

    //返回第一行第一列那个对象
    public object ExecuteScalar(string strCommand, params SqlParameter[] param)
    {
        PreCommand(sqlConnection, strCommand, param);

        object temp = sqlCommand.ExecuteScalar();

        sqlConnection.Close();

        return temp;
    }

    //对数据库进行不返回对象的操作
    public void ExecuteNon(string strCommand, params SqlParameter[] param)
    {
        PreCommand(sqlConnection, strCommand, param);

        sqlCommand.ExecuteNonQuery();

        sqlConnection.Close();

    }

    //给SqlCommand添加参数
    public void AddParms(SqlParameter[] param)
    {
        if (param != null)
        {
            foreach (SqlParameter p in param)
                sqlCommand.Parameters.Add(p);
        }
    }

    //执行前准备工作
    public void PreCommand(SqlConnection sqlConnection, string strCommand, params SqlParameter[] param)
    {
        sqlCommand.CommandText = strCommand;
        sqlCommand.Connection = sqlConnection;

        AddParms(param);

        if (sqlConnection.State == ConnectionState.Closed)
            sqlConnection.Open();
    }
}