设计模式（抽象工厂模式）

开发中为了解决连接不同数据源使用了抽象工厂生成器来构造数据访问层，

namespace  Ehl.Atms.UI.IID
{
    /**//// <summary>
    /// 数据库工厂生成器
    /// </summary>
    internal class DataFactory
    {
        public DataFactory()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }
        /**//// <summary>
        /// 生成器
        /// </summary>
        /// <param name="connString">连接字符串</param>
        /// <param name="dbType">数据库类型</param>
        /// <returns></returns>
        public DataAbstract GetInstance(string connString,string dbType)
        {
            if( dbType.ToLower() == "oracle" )
            {
                return new DataOracle( connString );
            }
            else
            {
                return null;
            }
        }
    }
}

namespace  Ehl.Atms.UI.IID
{
     ///   <summary>
     ///  数据库连接工厂抽象类
     ///   </summary>
     internal   abstract   class  DataAbstract
    {
         ///   <summary>
         ///  查询数据
         ///   </summary>
         ///   <param name="strSql"></param>
         ///   <returns></returns>
         public   abstract  DataView Sql_Select(  string  strSql );
         ///   <summary>
         ///  执行Sql语句
         ///   </summary>
         ///   <param name="strSql"></param>
         public   abstract   void  Sql_Execute(  string  strSql );
         ///   <summary>
         ///  判断是否重复
         ///   </summary>
         ///   <param name="strSql"></param>
         ///   <returns></returns>
         public   abstract   bool  Sql_isExist(  string  strSql );
         ///   <summary>
         ///  关闭连接
         ///   </summary>
         public   abstract   void  Close();
    }
}

namespace  Ehl.Atms.UI.IID
{
     ///   <summary>
     ///  数据库工厂模式OracleO连接类
     ///   </summary>
     internal   class  DataOracle:DataAbstract
    {
         private  OracleConnection oracleConn ;
         private  OracleCommand oracleComm ;
         private  OracleDataAdapter oracleDa;
         public  DataOracle(  string  ConnectString )
        {
            oracleConn  =   new  OracleConnection( ConnectString );
            oracleConn.Open();
        }
         ///   <summary>
         ///  实现查询
         ///   </summary>
         ///   <param name="strSql"></param>
         ///   <returns></returns>
         public   override  DataView Sql_Select(  string  strSql )
        {
             try
            {
                DataSet ds  =   new  DataSet() ;
                 if ( strSql  !=   ""  ) 
                {
                     if ( oracleConn.State  ==  ConnectionState.Broken ) 
                    {
                        oracleConn.Close() ;
                        oracleConn.Open() ;
                    }
                    oracleComm  =  oracleConn.CreateCommand();
                    oracleComm.CommandType  =  CommandType.Text;
                    oracleComm.CommandText  =  strSql;
                    oracleDa  =   new  OracleDataAdapter( oracleComm );
                    oracleDa.Fill(ds);
                    oracleDa.Dispose();
                    oracleComm.Dispose();
                }
                 return  ds.Tables[ 0 ].DefaultView;
            }
             catch ( Exception ex ) 
            {
                Log.WriteLog(  string .Format(  " 类名称：{0} 方法名称：{1} 消息： {2} "  ,  " DataOracle "  ,  " Sql_Select "  , ex.ToString() ) ,  true  ) ;
                 return    new  DataView() ;
            }

        }
         ///   <summary>
         ///  执行Sql
         ///   </summary>
         ///   <param name="strSql"></param>
         public   override   void  Sql_Execute( string  strSql)
        {
             try
            {
                ExecuteNonQuery( strSql );
            }
             catch ( Exception ex )
            {
                Log.WriteLog(  string .Format(  " 类名称：{0} 方法名称：{1} 消息： {2} "  ,  " DataOracle "  ,  " Sql_Execute "  , ex.ToString() ) ,  true  ) ;
            }
        }

         public   override   bool  Sql_isExist( string  strSql)
        {
             try
            {    
                 bool  flag  =   false ;
                 if ( strSql.Trim()  !=   "" )
                {
                     if ( oracleConn.State  ==  ConnectionState.Broken ) 
                    {
                        oracleConn.Close() ;
                        oracleConn.Open() ;
                    }
                    oracleComm  =  oracleConn.CreateCommand( ) ;
                    oracleComm.CommandType  =  CommandType.Text ;
                    oracleComm.CommandText  =  strSql ;
                     if (oracleComm.ExecuteScalar()  !=   null  )
                    {
                        flag  =   true ;
                    }
                    oracleComm.Dispose();
                }
                 return  flag;
            }
             catch ( Exception ex )
            {
                Log.WriteLog(  string .Format(  " 类名称：{0} 方法名称：{1} 消息： {2} "  ,  " DataOracle "  ,  " Sql_isExist "  , ex.ToString() ) ,  true  ) ;
                 return   true ;
            }
        }



         ///   <summary>
         ///  执行批处理的sql语句
         ///   </summary>
         private   int  ExecuteNonQuery(  string  strSql ) 
        {
             try
            {
                 int  iRecordCount  =   0  ;
                strSql  =  strSql.Trim() ;
                 if ( strSql  !=   ""  ) 
                {
                    strSql  =  ( strSql.Substring( strSql.Length  -   1  ,  1  )  ==   " ; "  )  ?   strSql : strSql  +   " ; "  ;
                     if ( oracleConn.State  ==  ConnectionState.Broken ) 
                    {
                        oracleConn.Close() ;
                        oracleConn.Open() ;
                    }
                    oracleComm  =  oracleConn.CreateCommand( ) ;
                    oracleComm.CommandType  =  CommandType.Text ;
                    oracleComm.CommandText  =   string .Format(  " begin {0} end ; "  , strSql ) ;
                    iRecordCount  =  oracleComm.ExecuteNonQuery() ;
                    oracleComm.Dispose();
                }
                 return  iRecordCount ;
            }
             catch ( Exception ex ) 
            {
                Log.WriteLog(  string .Format(  " 类名称：{0} 方法名称：{1} 消息： {2} "  ,  " DataOracle "  ,  " ExecuteNonQuery "  , ex.ToString() ) ,  true  ) ;
                 return    0  ;
            }
        }
         ///   <summary>
         ///  关闭连接
         ///   </summary>
         public   override   void  Close()
        {
            oracleConn.Dispose();
            oracleConn.Close();
        }

    }
}