But if you know the ID of something and you want to update it, why do a round trip to read it first, then to do another round trip to update it like you could have in the first place?
Regards, Greg Dr Greg Low 1300SQLSQL (1300 775 775) office | +61 419201410 mobile│ +61 3 8676 4913 fax SQL Down Under | Web: www.sqldownunder.com<http://www.sqldownunder.com/> | http://greglow.me<http://greglow.me/> From: ozdotnet-boun...@ozdotnet.com [mailto:ozdotnet-boun...@ozdotnet.com] On Behalf Of David Rhys Jones Sent: Tuesday, 20 September 2016 8:03 PM To: ozDotNet <ozdotnet@ozdotnet.com> Subject: Re: Entity Framework - the lay of the land That's still the best way to update something Get the object first, then update that reference, instead of trying to attach a new object with the same Id. There is a performance hit, but you are updating it's not needed to be quick. If your requirement is speed when updating, then you shouldn't be using EF. Davy Si hoc legere scis nimium eruditionis habes. On Tue, Sep 20, 2016 at 11:53 AM, Greg Low (罗格雷格博士) <g...@greglow.com<mailto:g...@greglow.com>> wrote: Have they fixed the update situation yet? I remember that you had to select something before you could update it. (At least previously) Regards, Greg Dr Greg Low 1300SQLSQL (1300 775 775) office | +61 419201410<tel:%2B61%20419201410> mobile│ +61 3 8676 4913<tel:%2B61%203%208676%204913> fax SQL Down Under | Web: www.sqldownunder.com<http://www.sqldownunder.com/> | http://greglow.me<http://greglow.me/> From: ozdotnet-boun...@ozdotnet.com<mailto:ozdotnet-boun...@ozdotnet.com> [mailto:ozdotnet-boun...@ozdotnet.com<mailto:ozdotnet-boun...@ozdotnet.com>] On Behalf Of David Rhys Jones Sent: Tuesday, 20 September 2016 7:20 PM To: ozDotNet <ozdotnet@ozdotnet.com<mailto:ozdotnet@ozdotnet.com>> Subject: Re: Entity Framework - the lay of the land I've been working with EF now for a few years, here's a list of what went wrong / what went right. Large public Website Good: No complex queries in EF, anything more than a couple of tables and a stored procedure is called. All objects from EF were transformed into new objects for use in the website Bad: The context was shared between processes and thusly began to grow after an hour or two, causing a slowdown of EF. Regular flushing solved this Updates into the database set the FK property but did not attach the object, this resulted in data being correct for a moment, but then overwritten with the original values when the savechanges was called. Large Multinational Bank - Bulk Processing Good: Most processing was done without EF, The website used EF to query the same data. Bad: Framework implemented IEnumerable as each interface, thus service.GetClients().Count() resulted in the entire table being returned. Changing the interface to IQueryable allowed the DB to do a count(*) Large Multinational, low use public website. Good: EF context is queried and disposed of as soon as possible, leaving the website responsive Bad: Bad design of the database has resulted in needless queries bringing back data that is not used. All EF generated queries are complicated. A mixture of stored procedures and EF context is used within a process resulting in incorrect values. I quite like EF, it's efficient to write queries in if you know what is being generated at the database level. I always output the SQL query to the debug window so I know what is being passed to the DB. But if the query is not self-contained and requires a lot of tables, then a specific stored procedure should be used. However, do not update with a stored procedure if you are using Entity to read back the values. Do POCO updates and read the linked objects and attach them correctly. Davy. Si hoc legere scis nimium eruditionis habes. On Tue, Sep 20, 2016 at 10:03 AM, David Connors <da...@connors.com<mailto:da...@connors.com>> wrote: On Tue, 20 Sep 2016 at 13:59 Greg Low (罗格雷格博士) <g...@greglow.com<mailto:g...@greglow.com>> wrote: I often get coy when I hear comparisons with Stack Overflow, Twitter, Facebook, Blog Engines, etc. though. Most of those platforms are happy to just throw away transactions when the going gets heavy. Also, most of their workloads are read-only and so highly cacheable at every layer of whatever architecture you choose. Once you throw consistency and transaction isolation under the bus shit gets pretty easy pretty quick. David. -- David Connors da...@connors.com<mailto:da...@connors.com> | @davidconnors | LinkedIn | +61 417 189 363<tel:%2B61%20417%20189%20363>
