连接数据库为什么抛出异常

2011-08-07 10:55:08 281 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

用STM32CubeMX和HAL库，5分钟搞定TB6612驱动直流电机（附完整代码）本文详细介绍了如何使用STM32CubeMX和HAL库快速配置TB6612驱动直流电机，包括硬件连接、CubeMX工程配置、电机驱动逻辑实现及进阶优化技巧。通过图形化工具和代码示例，即使是新手也能在5分钟内完成电机调速系统的搭建，大幅提升开发效率。阅读详情



        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            //create & open a SqlConnection

            SqlDataReader reader = null;

            SqlConnection cn = new SqlConnection(connectionString);

                try

                {

                    cn.Open();

                    //call the private overload that takes an internally owned connection in place of the connection string

                    reader = ExecuteReader(cn, null, commandType, commandText, commandParameters, SqlConnectionOwnership.Internal);

                }

                catch

                {

                    //if we fail to return the SqlDatReader, we need to close the connection ourselves

                    cn.Close();

                    MyDB._Check_Net = true;

                }

            return reader;

        }