mysql 時戳與日期轉換

• 日期轉時戳

select unix_timestamp('2013-01-01 10:10:10');

• 時戳轉日期

select from_unixtime(1355272360,'%Y/%m/%d %H:%i');

SQL語法優化

• 顯示各語法執行時間

set profiling=1;
SET profiling_history_size = 0;
SET profiling_history_size = 100;

＊＊＊ＳＱＬ語法＊＊＊

show profiles;

• 查看某個語法細節

show profile for query [profiles.Query_ID];

Asynchronous Programming with Async/Await

public async Task<string> GetHtmlAsync(string url)
{
 var webClient = new webClient();

 return await webClient.DownloadStringAsync(url);
}

Exception Handling

using(var temp = new class())
{

}

public class className():Exception
{
 public className(string message,Exception innerException)
  :base(message, innerException)
 {

 }
}

dynamic

dynamic

extension method

namespace system
{
 public static class stringExtension
 {
  public static string stringMethod(this String str, int aaa)
  {
   your method...
  }
 }
}

event

Event
EventHandler<>