ADO.NET Provider for Open Exchange Rates

Build 21.0.7930

Automatically Caching Data

Automatically caching data is useful when you do not want to rebuild the cache for each query. When you query data for the first time, the provider automatically initializes and builds a cache in the background. When AutoCache = true, the provider uses the cache for subsequent query executions, resulting in faster response times.

Configuring Automatic Caching

Caching the Projects Table

The following example caches the Projects table in the file specified by the CacheLocation property of the connection string.

C#

String connectionString = "Cache Location=C:\\cache.db;AutoCache=true;AppId=abc1234;";
using (OpenExchangeRatesConnection connection = new OpenExchangeRatesConnection(connectionString)) {
  OpenExchangeRatesCommand cmd = new OpenExchangeRatesCommand("SELECT Id, Statistics_ViewCount FROM Projects WHERE Id = 'MyId'", connection);
  OpenExchangeRatesDataReader rdr = cmd.ExecuteReader();
  while (rdr.Read()) {
    Console.WriteLine("Read and cached the row with Id " + rdr["Id"]);
  }
}

VB.NET

Dim connectionString As [String] = "Cache Location=C:\\cache.db;AutoCache=true;AppId=abc1234;"
Using connection As New OpenExchangeRatesConnection(connectionString)
  Dim cmd As New OpenExchangeRatesCommand("SELECT Id, Statistics_ViewCount FROM Projects WHERE Id = 'MyId'", connection)
  Dim rdr As OpenExchangeRatesDataReader = cmd.ExecuteReader()
  While rdr.Read()
	  Console.WriteLine("Read and cached the row with Id " + rdr("Id"))
  End While
End Using

Common Use Case

A common use for automatically caching data is to improve driver performance when making repeated requests to a live data source, such as building a report or creating a visualization. With auto caching enabled, repeated requests to the same data may be executed in a short period of time, but within an allowable tolerance (CacheTolerance) of what is considered "live" data.

Copyright (c) 2021 CData Software, Inc. - All rights reserved.
Build 21.0.7930