WebJul 25, 2024 · The following MS Docs article, Disconnected entities, says that just using an Update will act as an AddOrUpdate from EF Core 2.0 onwards, as long as the primary key column in the database has an auto-generated (eg identity) value. To quote from the article: If it is known whether or not an insert or update is needed, then either Add or Update … WebAlso, after every Add(..) or Update(..) I remove the tracking of the new entity: _context.Users.Add(user); await _context.SaveChangesAsync(); _context.Entry(user).State = EntityState.Detached; The problem arises if I add (or update) a new entity that has a reference to an already existing entity (meaning already stored in the database). For ...
In Entity Framework, what is the difference between Add and Attach …
WebOct 7, 2024 · Answers. Add is for adding newly created objects that do not exist in the database, on the other hand Attach is for entities that already exist in the database. when you use Attach you tell the context that the entity is already in the database, SaveChanges will have no effect over attached entities. Add, on the other hand, changes the state of ... WebThe deferred execution feature means that Entity Framework won't bother fetching until the call to SaveChanges is made; at which point an update statement will be generated per entity. Something like update a set a.[Name] = @0, a.[Address] = @1 from [someTable] as a where a.[Id] = @2;. – buy rite grocery store locations
c# - Attach for Update Entity Framework - Stack Overflow
WebMay 29, 2024 · They are different. Add creates a newly created instance of your DbSet type to the DbContext with the Added EntityState. When you call SaveChanges () on the the … WebApr 12, 2024 · The reason the update or insert pattern works with the primary key in the MSDN sample is because it is flagged as an Identity field. When you add an entity to a DbContext, EF gives the Id field a default value of 0, and the database will assign a unique value to the row when the INSERT is executed. WebJan 12, 2024 · Simple query and update. Query then insert, update, and delete. Each DbContext instance tracks changes made to entities. These tracked entities in turn drive the changes to the database when SaveChanges is called. This document presents an overview of Entity Framework Core (EF Core) change tracking and how it relates to queries … ceramic tiler hourly rate