entity-framework-6

问题 My application has no parameterless constructor at my DbContext implementation and I don't like to provide a parameterless constructor to a IDbContextFactory<> implementation. The reason is I want to keep control where the DbContext points to. That's why all my constructors will ask for the ConnectionStringProvider. public class MyDbContext : DbContext { internal MyDbContext(IConnectionStringProvider provider) : base(provider.ConnectionString) {} } and public class MyContextFactory :

问题 I am trying to perform an update through EF 6 and having trouble. I am relatively new to EF so please forgive me if the question is a bit dim. I am getting the following error When I try and update the instrument table: The entity type HashSet`1 is not part of the model for the current context. I think this is because of the nested objects. Does anyone know how to populate these? Thanks in advance. please see the code below of my update and model. try { var i = (from x in _entities.Instrument

问题 I created a very simple test project using Entity Framework 6 Code-first and I'm trying to understand how change tracking works. In my simple test I have a Blogs table and I insert a Blog with a name "User1", after inserting and saving I modify the object used to insert (name="User1 modified") but without saving changes. Right after that I query my database. For my surprise the query from the db is returning the modified record even though I did not save my changes after the update. Why is

问题 Recently I started using EF+ on our project with great success however sometimes I run into an issue that I have a set of entities for which I need to run a separate query. So if I have a set of 20 customers I need to run 20 queries separately. I wonder if there is way how to avoid this using EF+ FutureValue() somehow in a foreach loop. See this sample code: foreach (var customer in customers) { customer.SomeValue = ctx.SomeDatabaseTable.Where(myCondition).FutureValue(); // this would run 20

问题 I am trying to override Savechanges in My Database Context to mark my entites as SoftDeleted. I have an ISoftDeletable base which i override in my Entity classes public interface IsoftDeletable { public bool IsDeleted {get; set;} } And then in my Context public override int SaveChanges() { foreach (var entry in ChangeTracker.Entries() .Where(p => p.State == EntityState.Deleted)) SoftDelete(entry); return base.SaveChanges(); } private void SoftDelete(DbEntityEntry entry) { var entity = entry

问题 We just upgraded to Oracle 19c (19.3.0) and all apps stopped working with this error message: Oracle Data Provider for .NET does not support Oracle 19.0.48.0.0 I updated Oracle.ManagedDataAccess.EntityFramework and Oracle.ManagedDataAccess to 19.3.0 Any solution? 来源： https://stackoverflow.com/questions/57717088/oracle-data-provider-for-net-does-not-support-oracle-19-0-48-0-0

问题 I'm trying to use dbfunction from EF6 on database MySQL but I get the follow exception "FUNCTION database.DiffDays does not exist". I used this code: var aux = bd.Atos.Where(w => w.IdAtivo == 1 && w.IdUtilizador == idUtilizador && DbFunctions.DiffDays(DbFunctions.AddDays(w.Data, w.NumDias).Value, DateTime.Now).Value < numeroDias) What I'm missing? 来源： https://stackoverflow.com/questions/24442260/function-database-adddays-does-not-exist

问题 I'm trying to use dbfunction from EF6 on database MySQL but I get the follow exception "FUNCTION database.DiffDays does not exist". I used this code: var aux = bd.Atos.Where(w => w.IdAtivo == 1 && w.IdUtilizador == idUtilizador && DbFunctions.DiffDays(DbFunctions.AddDays(w.Data, w.NumDias).Value, DateTime.Now).Value < numeroDias) What I'm missing? 来源： https://stackoverflow.com/questions/24442260/function-database-adddays-does-not-exist

问题 I use Entity Framework 6 and i currently have a query with many includes which loads about 1200 entities into the dbContext. Loading the entities seems to be quite slow as the query takes almost a minute. Is there anything I can do about the performance? I have 4 such queries that take 2.5 minutes to load? LazyLoading is enabled but for performance reasons i preload the entities. var report = DbContext.REPORT.Single(r => r.ID == reportId); //this query takes a bit less than 1 minute DbContext

问题 In my web project I'm using EF6 and I'd like to log generated SQL for debugging purpose. I'm also using log4net to handle logs, so I'm looking for a way to integrate them together. What's the correct way to achieve this? 回答1: At the moment I'm using this approach: in my BaseController I have something like this: public class BaseController { protected MyDbContext DataContext { get; set; } protected readonly ILog logger; public BaseController() { DataContext = new MyDbContext(); logger =