Prevent EF Core From Updating A Column In A Specific Instance

EF Core Update The instance of entity type 'Ads' cannot be tracked

You are ...new...'ing up your own entity, when, you should just get that entity you've already added from the context:...Ads adsResult = new Ads() { Id = 1, AdsName = "UpdateAds1" }; _AdsService.UpdateAds(adsResult); ...With this code, Entity Framework is saying, "Hey, I already have an entity with that key (check your constructor, you're putting a...

Prevent updates to navigation properties in EF-core

It seems like your navigation properties have values, please check your navigation property have null reference before to save; EF Core save logic try to save navigation properties if they have value....Let me know if this is useful

In EF Core how to select specific column and also save

In addition to Table Splitting, which treats the content as a separate, related entity, EF supports updates of just selected columns....So you can construct an entity with a subset of its properties, and then mark the non-retrieved properties as unchanged. EG:... public async Task DoSomething(int id) { // select only nee...

EF Core - Can I make Entity Framework map only to only specific columns in the database?

By convention, public properties with a getter and a setter will be included in the model....You can use Data Annotations or Fluent API to exclude a property from the model....Data Annotation:...class Report { public string Id { get; set; } public string Name { get; set; } public string Description { get; set; } [NotMapped] pub...

EF Core return specific columns from child tables

I haven't seen that syntax for sub-objects before. eg:...ProjectType = { Type = p.ProjectType.Type } ...I believe that should be:...ProjectType = new ProjectTypeDTO{ Type = p.ProjectType.Type }

EF Core: prevent individual queries when updating data

If you wan to reduce database queries and you don't need latest changes to database you should cache the data, use a temporary variable to cache data and add .ToList() at the end of your query to prevent lazy loading.

EF core Database specific columns to nested object

a primary key to be defined in your Bar class....public class Bar { [Key] public int Something { get; set; } public int SomethingElse { get; set; } }

Select specific table columns to list async using EF Core

I think you want something like this. I changed your GetAllAsync method a little bit. Just, for example, we have Model class....class Model { public string Val { get; set; } } ...I moved your method to a helper class and made method generic. It takes 2 generic type, 1 for IQueryable type, 1 for the return type. the first parameter of the metho...

How to prevent a column update in EF Core 3.1?

According to the obsoleted property ...implementation...:...public virtual bool IsStoreGeneratedAlways { get => AfterSaveBehavior == PropertySaveBehavior.Ignore || BeforeSaveBehavior == PropertySaveBehavior.Ignore; set { if (value) { BeforeSaveBehavior = PropertySaveBehavior.Ignore; AfterSaveBehav...

EF Core Update updates all columns even though only one has changed

It was my understanding that EF Core has a "Change Tracker"...That's correct and that's why, once entities are attached to the context, you're exempted from marking them as updated. After the line......book.Title += " x"; ......EF detects this change and marks marks ...Title... as modified. No need to call the ...Update... method....This is the so-...