c#下各种数据库操作的封装！(支持ACCESS,SQLSERVER,DB2,ORACLE,MYSQL)（二）

使用静态工厂模式，通过传入枚举型参数，动态创建访问实例实现模式上采用基本实现接口，派生类继承基类的虚函数，从而实现代码的耦合较低，有很好的扩展性。

publicenum DBType




...{


Access,


SQL,


DB2,


Oracle,


MySQL


}




publicstaticclass DBAccessFactory




...{


publicstatic IDBAccess Create(DBType type)




...{


IDBAccess IRet = null;


switch (type)




...{


case DBType.Access:


IRet = new Access(type);


break;




case DBType.SQL:


IRet = new SQL(type);


break;




default:


break;


}


return IRet;


}




privateabstractclass DBAccess : IDBAccess




...{


protected DbConnection m_oConn = null;


protectedconststring CON_strServer = "Server";


protectedconststring CON_strDataBase = "Data Source";


protectedconststring CON_strUser = "UID";


protectedconststring CON_strPwd = "PWD";


protectedconststring CON_strConnTimeOut = "Connect Timeout = 2";


private DBType m_eDBType = DBType.Access;




protected DBAccess(DBType type)




...{


this.m_eDBType = type;


}




public DBType DBType




...{




get...{ returnthis.m_eDBType; }


}




publicvoid Init(string strServer, string strDataBase, string strUser, string strPwd)




...{


this.InitConn(strServer, strDataBase, strUser, strPwd);


}




publicvoid Open()




...{


if (this.m_oConn != null)




...{


this.m_oConn.Open();


}


}




publicint RunNoQuery(string strCmd)




...{


int iRet = 0;


try




...{


DbCommand oCmd = this.GetCmd(strCmd);


if (oCmd != null)




...{


iRet = oCmd.ExecuteNonQuery();


}


}


catch (Exception ex)




...{


throw (new Exception(ex.Message));


}


return iRet;


}




publicint GetFiledMax(string strTable, string strField)




...{


int iRet = -1;


DataTable dt = this.RunQuery("Select Max(" + strField + ") From " + strTable);


if (dt != null && dt.Rows.Count == 1)




...{


iRet = dt.Rows[0][0] is DBNull ? 0 : Convert.ToInt32(dt.Rows[0][0]);


}


return iRet;


}




public DataTable RunQuery(string strCmd)




...{


DataTable dt = new DataTable();


DbDataAdapter adp = this.DbAdp;


adp.SelectCommand = this.GetCmd(strCmd);


adp.Fill(dt);


return dt;


}




publicvoid Close()




...{


if (this.m_oConn != null && this.m_oConn.State == System.Data.ConnectionState.Open)




...{


this.m_oConn.Close();


}


}




publicbool TestConn()




...{


bool bRet = true;


try




...{


if (this.m_oConn.State != System.Data.ConnectionState.Open)




...{


this.m_oConn.Open();


}


bRet = this.m_oConn.State == System.Data.ConnectionState.Open;


}


catch




...{


bRet = false;


}


this.Close();


return bRet;


}






publicabstract DataTable Tables ...{ get; }


publicabstract DataTable GetColumns();


publicabstract DataTable GetColumns(string strTable);




protectedabstractvoid InitConn(string strServer, string strDataBase, string strUser, string strPwd);


protectedabstract DbCommand GetCmd(string strCmd);




protectedabstract DbDataAdapter DbAdp ...{ get;}


}


}