Redis caching with ServiceStack OrmLite and SQL Server persistence

Question

We have a Web app (ASP.NET/C#) with SQL Server backend. We use ServiceStack OrmLite as our POCO Micro ORM. We would now like to extend a part of our app to cache frequently-read data (mainly a collection of POCO objects as values, with numeric keys). But I'm not sure how to go about integrating a simple caching solution (in-memory or Redis based) that works seamlessly with OrmLite and MSSQL as the Master database.

I've read about the ServiceStack Redis Client, MemoryCacheClient and Multi nested database connections (OrmLiteConnectionFactory), but I couldn't find any examples, tutorial or code samples to learn more about implementing caching that works with OrmLite.

Any suggestions or links will be helpful and much appreciated.

Answer 1

You'd need to implement the caching logic yourself, but it's not much work - here's a pseudocode example:

    public class QueryObject
    {
        public DateTime? StartDate { get; set; }
        public string SomeString { get; set; }
    }

    public class Foo
    {
        public DateTime DateTime { get; set; }
        public string Name { get; set; }
    }

    public class FooResponse
    {
        public List<Dto> Data { get; set; }
    }


    public FooResponse GetFooData(QueryObject queryObject)
    {
        using (var dbConn = connectionFactory.OpenDbConnection())
        using (var cache = redisClientsManager.GetCacheClient())
        {
            var cacheKey = string.Format("fooQuery:{0}", queryObject.GetHashCode()); //insert your own logic for generating a cache key here
            var response = cache.Get<Response>(cacheKey);

            //return cached result
            if (response != null) return response;

            //not cached - hit the DB and cache the result
            response = new FooResponse()
                {
                    Data =
                        dbConn.Select<Foo>(
                            x => x.DateTime > queryObject.StartDate.Value && x.Name.StartsWith(queryObject.SomeString)).ToList()
                };
            cache.Add(cacheKey, response, DateTime.Now.AddMinutes(15)); //the next time we get the same query in the next 15 mins will return cached result
            return response;

        }
    }