Updating data linq Chatlivesxe
Use the Update Definition Builder to build the Update Definition.
field, pass an entirely new document as the second argument to the Replace One Async method.
I went about implementing something similar to what Jeffrey envisioned and I’ll explain some of the hurdles I had to overcome to achieve it.
Since I recently converted my site to blogengine.net, I’ll use its database schema for all examples to follow.
This is a perfect example of when a O/R Mapping framework issues multiple delete statements when a single ‘simple’ SQL statement could be written.
, will create the field if the field does not exist. In the C# driver, the Update Definition document defines the update operations to perform.
In the C# Driver documentation, see Update One Async, Update Many Async, Update Definition, and Replace One Async.
In Mongo DB, write operations are atomic on the level of a single document.
One problem that I can't seem to resolve with the data context is how to update Entities based on POCO objects that didn't originate out of the Data Context.In case you didn’t read the article, it discusses the downside of most O/R Mapping frameworks when it comes to multiple updates or deletes.He states the fact that a SQL statement for row flagged as update/delete in the entity set is created.As you can see in the snippet below, I select a record, update it ... Change Conflict Exception saying "Row not found or changed". I'm sure that nobody modifies or deletes the data in the meantime. When LINQ to SQL selects a record, it does not lock any data.
and a few lines later the update crashes with a lovely System. When it is updating a record, it compares all columns with their original values. The update query that I expected from LINQ to SQL was: This still does neither explain nor solve my issue, since my original values did not change in the meantime.
That's what I would expect from an Attach method that takes two object parameters. Attach(customer, true); Nope doesn't like that either. How hard could it possibly be to reattach an entity that is actually mapped by the entity manager? I would expect that if you pass in a context loaded object to compare against, that LINQ should be able to reestablish proper update status.