Question

If I cache a entire table:

static List<Table1> table1Cache = context.Table1.ToList();

Then I use it to associate:

var context = new Context();
var t2 = new Table2();
t2.MyTable1Reference = table1Cache.Single(x=>x.Id == paramIntId);
context.SaveChanges();

A new row will be inserted to Table1, because of the third line. EF thinks that is a new entity. I know that I can do somethings like always Attaching the cache when create de context(I have 1 context per Request), or use MyTable1ReferenceID = table1Cache.Single(x=>x.Id == paramIntId).Id;

But its not secure, I can forget sometimes, there is a good solution?

Answer 1

yes, that makes sense because the entity is not currently associated with the current context. therefore EF thinks it’s transient and saves a new instance.

if you are caching across contexts, then you don’t want to store the object itself. that is related to the context. instead you want to store the data in cache. basically serializing and deserializing the entity. You will also need to associate the entity when the current context so the next time it’s retrieved from cache you can save change to both the cache and the database.

if all this sounds like a lot, it is. keeping 2 data stores synchronized is not an easy problem to solve. I would take a look at the implementation of 2nd level cache for NHibernate.