public void QueryWithOverwriteChangesWillShowDeletedEntitiesAsDeleted()
{
// Create initial data in database
int sueID = CustomerHelpers.AddCustomer("Sue", "VA");
using (var context1 = new EFTestContext())
{
// Get Sue's customer entity, adding it to the cache
var sue = context1.Customers.First(c => c.ID == sueID);
// Name should be "Sue"
sue.Name.Should().Be("Sue");
// Delete data in other context (simulating a second user)
using (var context2 = new EFTestContext())
{
var sueToDelete = context2.Customers.First(c => c.ID == sueID);
context2.Customers.Remove(sueToDelete);
context2.SaveChanges();
}
// Verify the data has been deleted from the database
using (var context3 = new EFTestContext())
{
var sueIsDeleted = context3.Customers.FirstOrDefault(c => c.ID == sueID);
sueIsDeleted.Should().BeNull();
}
// Get Sue's customer entity using MergeOptions.OverwriteChanges, updating the entity in the cache
var objectContext = ((IObjectContextAdapter)context1).ObjectContext;
var objectQuery = objectContext.CreateObjectSet <Customer>().Where(c => c.ID == sueID);
// Set the MergeOptions to overwrite what is in the cache
(objectQuery as ObjectQuery <Customer>).MergeOption = MergeOption.OverwriteChanges;
var sueFromOriginalContext = objectQuery.FirstOrDefault();
// Verify that sue does not exist
sueFromOriginalContext.Should().BeNull();
// Caution: the original sue object we created doesn't know it's been deleted
context1.Entry(sue).State.Should().Be(EntityState.Unchanged);
// Caution: The original object still exists
sue.Should().NotBeNull();
sue.Name.Should().Be("Sue");
}
}
public void ReloadEntityWillForceEFToUpdateEntityInCache()
{
// Create initial data in database
int sueID = CustomerHelpers.AddCustomer("Sue", "VA");
using (var context1 = new EFTestContext())
{
// Get Sue's customer entity
var sue = context1.Customers.Where(c => c.ID == sueID).First();
// Name should be "Sue"
sue.Name.Should().Be("Sue");
// Update data in other context (simulating a second user)
using (var context2 = new EFTestContext())
{
context2.Customers.First(c => c.ID == sueID).Name = "Susan";
context2.SaveChanges();
}
// Verify the name has been updated in the database
using (var context3 = new EFTestContext())
{
var sueIsUpdated = context3.Customers.First(c => c.ID == sueID);
sueIsUpdated.Name.Should().Be("Susan");
}
// Verify our original context has the old data
var sueNotUpdated = context1.Customers.First(c => c.ID == sueID);
sueNotUpdated.Name.Should().Be("Sue");
// Force EF to reload Sue's data
context1.Entry(sue).Reload();
// Retrieve the updated record from context1, which shows us
// that the cache has been updated
var sueUpdatedInOriginalContext = context1.Customers.First(c => c.ID == sueID);
sueUpdatedInOriginalContext.Name.Should().Be("Susan");
}
// Cleanup
CustomerHelpers.DeleteCustomer(sueID);
}
public void GetDatabaseValuesWillUpdateTheCache()
{
// Create initial data in database
int sueID = CustomerHelpers.AddCustomer("Sue", "VA");
using (var context1 = new EFTestContext())
{
// Get Sue's customer entity
var sue = context1.Customers.First(c => c.ID == sueID);
// Name should be "Sue"
sue.Name.Should().Be("Sue");
// Update data in other context (simulating a second user)
using (var context2 = new EFTestContext())
{
context2.Customers.First(c => c.ID == sueID).Name = "Susan";
context2.SaveChanges();
}
// Verify the name has been updated in the database
using (var context3 = new EFTestContext())
{
var sueIsUpdated = context3.Customers.First(c => c.ID == sueID);
sueIsUpdated.Name.Should().Be("Susan");
}
// Verify we still have stale data in the cache
var sueNotUpdated = context1.Customers.First(c => c.ID == sueID);
sueNotUpdated.Name.Should().Be("Sue");
// Use GetDatabaseValues to get a dictionary of the current db values (ignoring the cache)
DbPropertyValues sueDbValues = context1.Entry(sueNotUpdated).GetDatabaseValues();
sueDbValues["Name"].Should().Be("Susan");
// Verify we still have stale data in the cache
var sueStillNotUpdated = context1.Customers.First(c => c.ID == sueID);
sueStillNotUpdated.Name.Should().Be("Sue");
}
// Cleanup
CustomerHelpers.DeleteCustomer(sueID);
}
public void Update(int id, T obj)
{
dbSet.Attach(obj);
_context.Entry(obj).State = EntityState.Modified;
_context.SaveChanges();
}