Re0:在.NetCore 中Dapper的基本用法

整理一下目前在用的Dapper

与FrameWork不同，NetCore数据库配置需要从appsettings.json中获取

刚接触的时候被这块坑了，自己手动建了个app.config。然后你懂的（笑哭）

读取配置文件：

public class AppSetting
    {
        private static readonly object objLock = new object();
        private static AppSetting instance = null;

        private IConfigurationRoot Config { get; }

        private AppSetting()
        {
            var builder = new ConfigurationBuilder()
             .SetBasePath(Directory.GetCurrentDirectory())
             .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
            Config = builder.Build();
        }

        public static AppSetting GetInstance()
        {
            if (instance == null)
            {
                lock (objLock)
                {
                    if (instance == null)
                    {
                        instance = new AppSetting();
                    }
                }
            }

            return instance;
        }

        public static string GetConfig(string name)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                return "name is null";
            }
            return GetInstance().Config.GetSection(name).Value;
        }
    }

日常够用的几个方法：

        /// <summary>
        /// 返回行数
        /// </summary>
        /// <param name="sql">SQL</param>
        /// <returns></returns>
        public static int Execute(string sql)
        {
            string URL = AppSetting.GetConfig("ConnectionStringsDapper:DB");
            IDbConnection conn = new SqlConnection(URL);
            int result = conn.Execute(sql);
            return result;
        }

        /// <summary>
        /// 返回List
        /// </summary>
        /// <param name="sql">SQL</param>
        /// <returns></returns>
        public static dynamic Query(string sql)
        {
            string URL = AppSetting.GetConfig("ConnectionStringsDapper:DB");
            IDbConnection conn = new SqlConnection(URL);
            dynamic result = conn.Query(sql);
            return result;
        }

        /// <summary>
        /// 返回单条
        /// </summary>
        /// <param name="sql">SQL</param>
        /// <returns></returns>
        public static dynamic QueryFirst(string sql)
        {
            string URL = AppSetting.GetConfig("ConnectionStringsDapper:DB");
            IDbConnection conn = new SqlConnection(URL);
            dynamic result = conn.QueryFirst(sql);
            return result;
        }            

Controller中调用：

    
　　　　　　string sql = "bula bula bula";
       　　dynamic result = Query(sql);

　　　　　　string sql = "bula bula bula";
    　　　 dynamic result = QueryFirst(sql);

　　　　　　string sql = "bula bula bula";
      　　 int result= Execute(sql);