如何将数据表存储在缓存中以重复使用？

Question

In my application i have used Generic handler to serve requests.

I want mechanism like if the first time request comes to handler ,it makes a request to server and then Cache whole datatable, so for upcoming request if the next requested productcode is exist in the datatable of cache, it should not go to server for fetching data again..it should check data of datatable only.

So can you explain me how can i set datatable in cache.??

Answer 1

Something along these lines?

public DataTable GetDataTableFromCacheOrDatabase()
{
   DataTable dataTable = HttpContext.Current.Cache["secret key"] as DataTable;
   if(dataTable == null)
   {
       dataTable = GetDataTableFromDatabase();
       HttpContext.Current.Cache["secret key"] = dataTable;
   }
   return dataTable;
}

You're going to need some mechanism to flush the data table from the cache if it changes. For example you could use an SqlCacheDependency .

As requested, to clear the cache an hour after the table is added you would do:

HttpContext.Current.Cache.Insert("secret key", dataTable, null, DateTime.Now.AddHours(1), System.Web.Caching.Cache.NoSlidingExpiration);

Answer 2

try this

 DataTable mytable;
 String key = "key"
 if(HttpContext.Current.Cache[Key] ==null)
 {
        mytable = GetDTFromDB();
        if(mytable.Rows.Count > 0)
            HttpContext.Current.Cache.Insert(strKey, mytable, Nothing, DateTime.Now.AddHours(1), System.Web.Caching.Cache.NoSlidingExpiration);
    else
        mytable = HttpContext.Current.Cache[strKey];
  }

Answer 3

您可以使用：

HttpContext.Current.Cache["CacheDataTableID"] = datatableInstance;

Answer 4

you can write a property for your table like

public DataTable CachedTable  { get{ 
      if(Cache["CachedTable"] == null) 
     { 
       Cache["CachedTable"]= //get from databse 
      } 
      return Cache["CachedTable"]; 
    }  }