工厂提供器DbProviderFactory 实现多种数据库类型类型的DBhelper

废话就不多说了。。直接上代码。。
希望还有什么不足之处 大家提出来。。

public class DbHelper
    {
         public  DbHelper()
         {
            
         }

         /// 得到web.config里配置项的数据库连接字符串。
         private static readonly  string ConnectionString=  ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
         /// 得到工厂提供器类型
         private static readonly  string ProviderFactoryString= ConfigurationManager.ConnectionStrings["Provider"].ToString();

          private static IDbConnection connection = null;
          private static DbProviderFactory df = null;
         
         /// <summary>
          /// 创建工厂提供器并且
         /// </summary>
          private static IDbConnection CreateConnection()
          {
               df = DbProviderFactories.GetFactory(ProviderFactoryString);
              connection = df.CreateConnection();
              connection.ConnectionString = ConnectionString;
              return connection;
          }



         /// <summary>
         /// 创建命令对象
         /// </summary>
         /// <returns></returns>
         private static IDbCommand CreateDbCommand()
         {
            IDbConnection con=  CreateConnection();//创建工厂提供器并且
             IDbCommand cmd = df.CreateCommand();
             cmd.Connection = con;
             return cmd;
         }
         /// <summary>
         /// 创建Adapter对象
         /// </summary>
         /// <returns></returns>
         private static IDbDataAdapter CarateAderDataAdapter()
         {
             IDbConnection con = CreateConnection();//创建工厂提供器并且
             IDbDataAdapter Adapter = df.CreateDataAdapter();
             
             return Adapter;
         }
         


         /// <summary>
         /// 准备命令参数 
         /// </summary>
         /// <param name="cmd">IDbCommand 命令对象</param>
         /// <param name="con">数据库连接对象</param>
         /// <param name="comType">解释命令字符串</param>
         /// <param name="comText">命令文本</param>
         /// <param name="parameter">数据操作命令参数化</param>
         /// <returns></returns>
         private static void PrepareCommand(IDbCommand cmd, IDbConnection con, IDbTransaction trans, CommandType comType, string comText, params IDbDataParameter[] parameter)
         {

             if (con.State != ConnectionState.Open)
                 con.Open();


             cmd.Connection = con;
             cmd.CommandType = comType;
           
             cmd.CommandText = comText;
             if (trans != null)
                 cmd.Transaction = trans;
             if (parameter != null)
             {
                 foreach (IDbDataParameter p in parameter)
                 {
                     // 检查未分配值的输出参数,将其分配以DBNull.Value.
                     if ((p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input) &&
                         (p.Value == null))
                     {
                         p.Value = DBNull.Value;
                     }
                     cmd.Parameters.Add(p);
                 }
             }
       
         }

         /// <summary>
         /// 执行增删改命令 cmdType参数是否调用存储过程。 为true 调用存储过程,false为sql语句
         /// </summary>
         /// <param name="cmdType">True为存储，False为文本</param>
         /// <param name="comText">命令语句</param>
         /// <param name="parameter">命令参数</param>
         /// <returns>返回影响行数</returns>
         public static int ExecuteNonQuery(string cmdText,bool cmdType, params IDbDataParameter[] parameter)
         {
             using (IDbConnection con = CreateConnection())
             {
                 IDbCommand cmd = CreateDbCommand();
                 CommandType type = CommandType.Text;
                 if (cmdType)
                     type = CommandType.StoredProcedure;  //存储过程
                 PrepareCommand(cmd, con, null, type, cmdText, parameter);
                 int i= cmd.ExecuteNonQuery();
                 cmd.Parameters.Clear();
                 return i;
             }

         }


         /// <summary>
         /// 轻量级查询，返回第一行第一列，失败或异常返回NULL
         /// </summary>
         /// <param name="cmdText">命令文本</param>
         /// <param name="parameter">命令参数化</param>
         /// <returns></returns>
         public static object ExecuteScalar(string cmdText, params IDbDataParameter[] parameter)
         {
             using (IDbConnection con = CreateConnection())
             {
                  IDbCommand cmd = CreateDbCommand();
                  PrepareCommand(cmd, con, null, CommandType.Text, cmdText, parameter);
                  object val = cmd.ExecuteScalar();
                  cmd.Parameters.Clear();
                  return val;
             }
         }


         /// <summary>
         /// 执行查询,cmdType参数是否调用存储过程。 为true 调用存储过程,false为sql语句
         /// </summary>
         /// <param name="cmdText">命令文本</param>
         /// <param name="parameter">命令参数</param>
         /// <returns>返回IDataReader接口</returns>
         public static IDataReader ExecuteReader(string cmdText,bool cmdType, params IDbDataParameter[] parameter)
         {
             try
             {

                 IDbCommand cmd = CreateDbCommand();
                 CommandType type = CommandType.Text;
                 if (cmdType)
                     type = CommandType.StoredProcedure;  //存储过程
                 IDbConnection con = CreateConnection();
                 PrepareCommand(cmd, con, null, type, cmdText, parameter);
                 return cmd.ExecuteReader(CommandBehavior.CloseConnection);
             }
             catch (Exception ex)
             {
                 throw ex;
             }
             
         }

         /// <summary>
         /// 查询结果，True为存储，False为文本
         /// </summary>
         /// <param name="cmdText">查询文本</param>
         /// <param name="cmdType">命令类型，True为存储，False为文本</param>
         /// <param name="parameter">文本参数</param>
         /// <returns>返回DataSet</returns>
         public static DataSet GetDataTable(string cmdText,bool cmdType, params  IDbDataParameter[] parameter)
         {
              DataSet ds = new DataSet();
              IDbDataAdapter dapader = CarateAderDataAdapter();
              dapader.SelectCommand = CreateDbCommand();
              if (cmdType)
              {
                  dapader.SelectCommand.CommandType = CommandType.StoredProcedure;
              }
              dapader.SelectCommand.CommandText = cmdText;
             if(parameter!=null)
             {
                 foreach(IDbDataParameter p in parameter)
                 {
                     dapader.SelectCommand.Parameters.Add(p);
                 }
             }
             dapader.Fill(ds);
             return ds;
         }

         /// <summary>
         /// 执行事务 参数Hashtable类型 KEY为事务的文本，VALUE为事务得参数
         /// </summary>
         /// <param name="SQLStringLis">value</param>
         /// <returns></returns>
         public static int ExecuteSqlTran(Hashtable SQLStringLis)
         {
             using (IDbConnection con = CreateConnection())
             {
                 con.Open();//打开连接
                 using (IDbTransaction trans = con.BeginTransaction(IsolationLevel.ReadCommitted))
                 {
                     IDbCommand cmd = CreateDbCommand();
                     int i = 0;
                     try
                     {
                         //循环
                         foreach (DictionaryEntry myDE in SQLStringLis)
                         {
                             string cmdText = myDE.Key.ToString();
                             IDbDataParameter[] pams = (IDbDataParameter[])myDE.Value;
                             PrepareCommand(cmd,con, trans, CommandType.Text, cmdText, pams);
                              i = cmd.ExecuteNonQuery();
                             cmd.Parameters.Clear();
                         }
                         trans.Commit();//提交事务
                         return i;
                     }
                     catch (DbException ex)
                     {
                         trans.Rollback();//出现异常 回滚事务
                         return 0;
                         throw ex;
                     }
                } 
             }
         }

用的全部是ado.net 对象中的接口。。采用DbProviderFactory 来更换数据库类型。。     private static DbProviderFactory df = DbProviderFactories.GetFactory(数据库类型：如：System.Data.SqlClient,System.Data.OleDb 等);
代码很简单我就多说了。老鸟们手下留情