数据的查询：private void FullTab() {        SqlConnection con1 = new SqlConnection();//创建数据库库链接            try            {                String con = "server=.;database=common_wjdl;uid=sa;pwd=db2008mima";//定义数据库连接信息                con1.ConnectionString = con;                con1.Open();//打开数据库                String sql = "select * from Fileuploaded";//创建语句查询所有数据                SqlDataAdapter ada1 = new SqlDataAdapter(sql, con);//SqlDataAdapter 对象。 用于填充DataSet （数据集）。                DataSet myset = new DataSet();                SqlCommand cmd = con1.CreateCommand();//创建数据库命令                cmd.CommandText = sql;                SqlDataReader reader = cmd.ExecuteReader(); //从数据库中读取数据流存入reader中            }            catch (SqlException ee1)            {                Console.WriteLine(ee1.Message);//打印异常信息            }            catch (IndexOutOfRangeException ee2) {                Console.WriteLine(ee2.Message);//打印异常信息            }        }        数据的插入：（大致都一样，只需修改SQL语句就行）            String con = "server=.;database=common_wjdl;uid=sa;pwd=db2008mima";//定义数据库连接信息                            con1.ConnectionString = con;                            con1.Open();//打开数据库                            String sql = "insert into Fileuploaded (FileID,FileName,FilePath,QRCodePath,FileSuffix) Values('"+fileNameSave+"','"+fileName+"','"+filePath+"','"+filePath+"','"+fileSuffix+"')";//创建语句向数据库插入数据                            SqlCommand cmd = con1.CreateCommand();//创建数据库命令                            cmd.CommandText = sql;                            cmd.ExecuteNonQuery();