I updated my solution from .Net 3.1 to .Net 6. Also updated the Npgsql nuget package from 5.0.10 to 6.0.4 as part of this upgrade.
Since then, I am receiving an error "Can't cast database type character to Guid" when I try to retreive data from the database.
My mapping in the context file is
entity.Property(e => e.UserId).HasColumnName("user_id").HasColumnType("CHAR(36)");
In C# class, this property is a GUID.
Is there some mapping update with the newer version of npgsql?
EF Core has a built-in value converter which implicitly converts .NET Guid properties to text columns (see docs. Note that PostgreSQL has a full UUID type - that's a better way to store GUIDs in the database, rather than as text.
This works in EF Core 6.0.4 - if you're encountering trouble, please produce a minimal, runnable code sample and add it to your question above.
Working 6.0 code:
await using var ctx = new BlogContext();
await ctx.Database.EnsureDeletedAsync();
await ctx.Database.EnsureCreatedAsync();
ctx.Blogs.Add(new Blog { Guid = Guid.NewGuid()});
await ctx.SaveChangesAsync();
_ = await ctx.Blogs.ToListAsync();
public class BlogContext : DbContext
{
public DbSet<Blog> Blogs { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
=> optionsBuilder
.UseNpgsql(#"Host=localhost;Username=test;Password=test")
.LogTo(Console.WriteLine, LogLevel.Information)
.EnableSensitiveDataLogging();
}
public class Blog
{
public int Id { get; set; }
public string Name { get; set; }
[Column(TypeName = "CHAR(36)")]
public Guid Guid { get; set; }
}
Related
I am trying the new functionality with EF Core 2.2. It is based on the following article. "Announcing Entity Framework Core 2.2"
https://blogs.msdn.microsoft.com/dotnet/2018/12/04/announcing-entity-framework-core-2-2/
I installed the following Nuget package.
I added the following to my model.
using NetTopologySuite.Geometries;
//New as of EF.Core 2.2
//[Required]
//[NotMapped]
public Point Location { get; set; }
During my application startup I get the following error in my Database Context on the following line:
Database.EnsureCreated();
System.InvalidOperationException
HResult=0x80131509
Message=The property 'Point.Boundary' is of an interface type ('IGeometry'). If it is a navigation property manually configure the relationship for this property by casting it to a mapped entity type, otherwise ignore the property using the NotMappedAttribute or 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.
Source=Microsoft.EntityFrameworkCore
You need to call UseNetTopologySuite(). Example here:
public class ApplicationDbContext : IdentityDbContext
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
{
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
IConfigurationRoot configuration = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json")
.Build();
var connectionString = configuration.GetConnectionString("DefaultConnection");
optionsBuilder.UseSqlServer(connectionString, opts => opts.UseNetTopologySuite());
}
public DbSet<Test> Tests { get; set; }
}
public class Test
{
public int Id { get; set; }
public Point Location { get; set; }
}
I ran into this problem because I had a
if (!optionsBuilder.IsConfigured) around everything in my OnConfiguring. I had to remove this in order to get add-migrations to work.
As Kyle pointed out you need to call UseNetTopologySuite(), but I would call it during ConfigureServices like this:
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services
.AddEntityFrameworkNpgsql()
.AddDbContext<MyDBContext>(opt =>
opt.UseNpgsql(Configuration.GetConnectionString("MyDBConnection"),
o=>o.UseNetTopologySuite()))
.BuildServiceProvider();
...
}
...
}
Im using web API to return data in azure table storage. Im returning a class that I 'm inheriting TableEntity in a class and adding properties but want to keep to the .Net convention of capitalized property names but also keep to the JavaScript/json convention of lowercase properties names.
I've tried adding the Json.net property attributes to the class but it appears to be ignored. E.g.:
[JsonProperty("id")]
public string ID {get;set;}
If the instance has a value set on ID, null is represent in the serialized result.
According to your description, I tested this issue on my side and found it works well on my side and Azure. Here is my detailed steps, you could refer to it.
Create a controller named UserInfoController in the Web API application with the Get function like this:
// GET: api/UserInfo
[HttpGet]
public async Task<string> Get()
{
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(<your-Storage-ConnectionString>);
CloudTableClient tableClient = storageAccount.CreateCloudTableClient();
CloudTable cloudTable = tableClient.GetTableReference("UserInfo");
TableQuery<User> query = new TableQuery<User>()
.Where(TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, "Grade Four"));
var results =await cloudTable.ExecuteQuerySegmentedAsync(query, null);
//Serialize the object to string by using the latest stable version of Newtonsoft.Json
string jsonString = JsonConvert.SerializeObject(results);
return jsonString;
}
Entity
public class User : TableEntity
{
public User(string partitionKey, string rowKey)
{
this.PartitionKey = partitionKey;
this.RowKey = rowKey;
}
public User() { }
[JsonProperty("id")]
public long ID { get; set; }
[JsonProperty("username")]
public string UserName { get; set; }
[JsonProperty("phone")]
public string Phone { get; set; }
[JsonProperty("age")]
public int Age { get; set; }
}
Result
Deploy the Web API application to Azure, then you could find the following result by calling the function via Fiddler.
In summary, please try to check the version of Json.NET you are using. If you aren't using the latest (9.0.1), then please try to upgrade to the latest version and run your application again to find whether it could work as expected.
FYI - while this doesn't answer the direct answer of how to get TableEntity to respect JSON.net attributes... I was able to solve the use case by overriding the ReadEntity and WriteEntity method in the inherited class:
e.g.
public class User : TableEntity{
//Upper case name
public string Name {get; set};
public override void ReadEntity(IDictionary<string, AzureTableStorage.EntityProperty> properties, OperationContext operationContext){
base.ReadEntity(properties, operationContext);
//lower case
this.Name = properties["name"];
}
I created Xamarin.Forms Windows UWP and Android application with shared project.
To both(UWP and Android) I imported latest stable NuGet packages:
Microsoft.EntityFramework version 1.0.0, Microsoft.EntityFramework.Sqlite version 1.0.0 and Xamarin.Forms 2.3.1.114.
On shared project I created very simple data model:
public class User
{
public int Id { get; set; }
public string UserName { get; set; }
public string Password { get; set; }
public string Notes { get; set; }
}
and very simple data context:
public class DataDbContext: DbContext
{
public static string DatabasePathName;
public DataDbContext()
: base()
{
}
public DataDbContext(DbContextOptions options)
: base(options)
{
}
public DbSet<User> Users { get; set; }
protected override void OnConfiguring(
DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlite(
String.Format("Filename={0}", DataDbContext.DatabasePathName));
base.OnConfiguring(optionsBuilder);
}
}
(The model uses, according to docs.efproject.net, an implicit definition of the field Id as the key and autoincrement.)
Now I initialize database: First set the platform dependent property DatabasePathName and second I'll add three User items to each. I assume that the values of these records will later be read from Resources. At this point, it is just I enter as literals. Records are saved by SaveChanges() method(both UWP and Android returns 3 (saved records)).
Now, if I run Windows UWP application and retrive these records by:
List<User> users = dbContext.Users.ToList();
and everything is as it should be. I read the records, so do I get a value which I put in a TextBlock control.
But if I use the same code in Xamarin Android Application, this code throws System.NotImplementedException exception.
I don't know why. Thank you for the advice.
There are still a few known issues with Xamarin's implementation of the .NET Standard. See aspnet/Microsoft.Data.Sqlite#255 for more details. We'll keep that issue up-to-date as Xamarin lights up.
I am creating an Xamarin.iOS app and a Realm database.I would like to keep my POCO objects separate from my RealmObject so what I did was use a repository pattern and within the repository I tried to use AutoMapper to map the POCO to the RealmObject
e.g. (subset)
public class PlaceRepository : IPlaceRepository
{
private Realm _realm;
public PlaceRepository(RealmConfiguration config)
{
_realm = Realm.GetInstance(config);
}
public void Add(Place place)
{
using (var trans = _realm.BeginWrite())
{
var placeRealm = _realm.CreateObject<PlaceRealm>();
placeRealm = Mapper.Map<Place, PlaceRealm>(place);
trans.Commit();
}
}
So, if I debug my code everything maps OK and placeRealm is populated OK but when I commit nothing gets saved to the Realm db. The following is my RealmObject
public class PlaceRealm : RealmObject
{
[ObjectId]
public string Guid { get; set; }
public string Title { get; set; }
public string Notes { get; set; }
}
and this is my POCO Place
public class Place
{
public string Guid { get; set; }
public string Title { get; set; }
public string Notes { get; set; }
}
And AutoMapper is initialized like so:
Mapper.Initialize(cfg =>
{
cfg.CreateMap<Place, PlaceRealm>();
cfg.CreateMap<PlaceRealm, Place>();
});
All standard stuff. Has anyone else managed to get something similar working?
Your poco 'Place' is called 'PlaceRealm'. I suspect that is a typo. (made edit)
I suspect that Automapper is instantiating a new object overwriting your original 'placeRealm' object.
Perhaps you could try
Mapper.Map(place, placeRealm);
in place of your current mapping.
which should just copy the values to your already instatiated and tracked object.
(no need to store the return value).
You might also want to make explicit which properties (3) you are mapping as currently Automapper will map all including those in the base class.
On a side note, you may run into performance issues with Automapper. I found it to be the performance bottleneck in some apps. ExpressMapper is a nice alternative.
I'm using the SimpleMembership.MVC3 package with my MVC3 application and I want to be able to access users from the table through Entity Framework
In examples for doing this with MVC4, you can simply create a POCO to mirror the User table that's been generated, add your DbSet in your DbContext implementation and then query the DbSet like you normally would, ie: context.Users.
This collection is always returning 0 items for me even though there are rows in the table. What am I doing wrong? Here's what I got so far:
[Table("User")]
public class User
{
public int Id { get; set; }
public string UserName { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
public class TestContext : DbContext
{
public DbSet<User> Users { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
base.OnModelCreating(modelBuilder);
}
}
In my service:
model.Accounts = context.Users.ToList();
Thanks!
You do not create your a POCO that mirrors the User table in order to access it directly from EF. There is already a POCO created by the Internet template when you created the project, which you can customize as described here. This same article also shows how you can access the user information by accessing EF directly. You do not create your own context, there is one already in place that you use. Here is a code snippet from that article.
var context = new UsersContext();
var username = User.Identity.Name;
var user = context.UserProfiles.SingleOrDefault(u => u.UserName == username);
var email = user.Email;
The article also has links to download the source code that demonstrates the details on how to do this.
I circumvented the membership classes entirely and implemented a pure EF membership system. I leveraged the System.Web.Helpers Crypto helpers to handle password hashing and just create the AuthCookie when needed.