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);