DBHelper类的使用操作

下面我给出一些基本的使用示例,基本能满足你大部分的数据库操作需要了.
//1)直接执行sql语句

//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values('haha')");
//        db.ExecuteNonQuery(cmd);
//2)执行存储过程

//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetStoredProcCommond("t1_insert");
//        db.AddInParameter(cmd, "@id", DbType.String, "heihei");
//        db.ExecuteNonQuery(cmd);
//3)返回DataSet

//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetSqlStringCommond("select * from t1");
//        DataSet ds = db.ExecuteDataSet(cmd);
//4)返回DataTable

//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetSqlStringCommond("t1_findall");
//        DataTable dt = db.ExecuteDataTable(cmd);
//5)输入参数/输出参数/返回值的使用(比较重要哦)

//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetStoredProcCommond("t2_insert");
//        db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
//        db.AddOutParameter(cmd, "@outString", DbType.String, 20);
//        db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);

//        db.ExecuteNonQuery(cmd);

//        string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
//        int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value

//6)DataReader使用

//      DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetStoredProcCommond("t2_insert");
//        db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
//        db.AddOutParameter(cmd, "@outString", DbType.String, 20);
//        db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);

//        using (DbDataReader reader = db.ExecuteReader(cmd))
//        {
//            dt.Load(reader);
//        }       
//        string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
//        int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value

//7)事务的使用.(项目中需要将基本的数据库操作组合成一个完整的业务流时,代码级的事务是必不可少的哦)
//    pubic void DoBusiness()
//    {
//        using (Trans t = new Trans())
//        {
//            try
//            {
//                D1(t);
//                throw new Exception();//如果有异常,会回滚滴
//                D2(t);
//                t.Commit();
//            }
//            catch
//            {
//                t.RollBack();
//            }
//        }
//    }

//    public void D1(Trans t)
//    {
//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetStoredProcCommond("t2_insert");
//        db.AddInParameter(cmd, "@timeticks", DbType.Int64, DateTime.Now.Ticks);
//        db.AddOutParameter(cmd, "@outString", DbType.String, 20);
//        db.AddReturnParameter(cmd, "@returnValue", DbType.Int32);

//        if (t == null) db.ExecuteNonQuery(cmd);
//        else db.ExecuteNonQuery(cmd,t);

//        string s = db.GetParameter(cmd, "@outString").Value as string;//out parameter
//        int r = Convert.ToInt32(db.GetParameter(cmd, "@returnValue").Value);//return value
//    }

//    public void D2(Trans t)
//    {
//        DbHelper db = new DbHelper();
//        DbCommand cmd = db.GetSqlStringCommond("insert t1 (id)values('..')");       
//        if (t == null) db.ExecuteNonQuery(cmd);
//        else db.ExecuteNonQuery(cmd, t);
//    }
//以上我们好像没有指定数据库连接字符串,大家如果看下DbHelper的代码,就知道要使用它必须在config中配置两个参数,如下:
//   
//       
//       
//    其实,DbHelper需要的仅仅是两个字符串,你可以自己修改,作成加密什么的...

//好了,就这样,DbHelper的代码是非常简单和透明的,只是在ado.net上做了一点小包装,改变了一下使用它的程序员的编码方式,去除掉一些比较"物理级"的编程概念,如connection的open和close之类的,使程序员更专注于业务逻辑代码的编写,少死掉点脑细胞,另外,统一了数据操作层的数据操作代码的风格和格式,维护起来很方便的