entity-framework-core

问题 I want to generate a query that uses an inner join for a one to one relationship using a navigation property. This is for an existing database that I cannot change. Here are what my entities look like: [Table("Info")] public class Info { [Key] public int InfoId { get; set; } public string Name { get; set; } public virtual MoreInfo MoreInfo { get; set; } } [Table("MoreInfo")] public class MoreInfo { [Key] public int InfoId { get; set; } public string OtherName { get; set; } public int

问题 I have a strange problem, maybe it is something that I'm missing out, but I have the following LINQ Lambda query: var ss = ctx.ShipZones.SelectMany( z => ctx.ShipDecks, (z, d) => new { Zone = z.ZIndex, Deck = d.DIndex, Value = ctx.Tags .AsExpandable() .Include(s => s.TagSettings.Device.System) .Where(s => s.TagSettings.TagTypeId == 171 && s.TagSettings.Device.System.Id == z.Id && s.TagSettings.Device.ControlArea.Contains(d.Id) ) .Average(s => s.Value) } ).ToList(); According to this article,

问题 I have the next Code in EF Core 3.1 in language VB.NET Dim supplierID as string="1545464" Dim results = (From pa In DC.product.AsNoTracking() Where pa.supplierID = supplierID Select pa) The exception throw is: The LINQ expression 'DbSet<product> .Where(p => Operators.CompareString( Left: p.supplierID, Right: __$VB$Local_supplierID_0, TextCompare: False) == 0)' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by

问题 Upon upgrade to EFCore 3.1 deprecated warnings appeared: Warning CS0618 'RelationalDatabaseFacadeExtensions.ExecuteSqlCommandAsync(DatabaseFacade, RawSqlString, params object[])' is obsolete: 'For the async execution of SQL queries using plain strings, use ExecuteSqlRawAsync instead. For the async execution of SQL queries using interpolated string syntax to create parameters, use ExecuteSqlInterpolatedAsync instead.' Warning CS0618 'RelationalDatabaseFacadeExtensions.ExecuteSqlCommand

问题 Adding EF Core to a NET Standard project introduces transitive dependency versions incompatible with NuGet packages in other projects I have a solution with multiple .NET Standard 2.0 projects. One Project A uses the Google.Protobuf (3.11.2) NuGet package, that depends on System.Memory (4.5.3) System.Buffers (4.4.0) System.Numerics.Vectors (4.4.0) System.Runtime.CompilerServices.Unsafe (4.5.2) A few other projects also depend on System.Memory and all use the same dependency versions . Another

问题 Adding EF Core to a NET Standard project introduces transitive dependency versions incompatible with NuGet packages in other projects I have a solution with multiple .NET Standard 2.0 projects. One Project A uses the Google.Protobuf (3.11.2) NuGet package, that depends on System.Memory (4.5.3) System.Buffers (4.4.0) System.Numerics.Vectors (4.4.0) System.Runtime.CompilerServices.Unsafe (4.5.2) A few other projects also depend on System.Memory and all use the same dependency versions . Another

问题 Before EF Core 3.0 this worked fine (evaluated on server+client): var exists = await _context.Countries.AsNoTracking().AnyAsync(x => x.CountryCode.Equals(country.CountryCode, StringComparison.OrdinalIgnoreCase)); What is the best/preferred method to translate the string.Equals(str, StringComparison.OrdinalIgnoreCase) -part now in EF Core 3.0, so that the query evaluates only on the server side. var exists = await _context.Countries.AsNoTracking().AnyAsync(x => x.CountryCode.ToUpper() ==

问题 I have 2 projects in my solution, I have a project with Entity Framework Core installed: And in the other ASP.NET Web API project I have these packages: <?xml version="1.0" encoding="utf-8"?> <packages> <package id="Antlr" version="3.5.0.2" targetFramework="net461" /> <package id="Microsoft.ApplicationInsights" version="2.5.1" targetFramework="net461" /> <package id="Microsoft.ApplicationInsights.Agent.Intercept" version="2.4.0" targetFramework="net461" /> <package id="Microsoft

问题 I have the below model. What is the better way to load the parent entity with child entity at the time of fetching from the DB with find method? Parent Entity: public class Client { public int Id { get; set; } public string LastName { get; set; } public string Gender { get; set; } public DateTime DateOfBirth { get; set; } public Address Address { get; set; } } Child Entity: public class Address { public int Id { get; set; } public string FirstLine { get; set; } public string SecondLine { get;

问题 I have an ASP.NET core 2.0 using Entity Framework core on a SQL Server db. I have to trace and audit all the stuff made by the users on the data. My goal is to have an automatic mechanism writing all what is happening. For example, if I have the table Animals, I want a parallele table "Audit_animals" where you can find all the info about the data, the operation type (add, delete, edit) and the user who made this. I already made this time ago in Django + MySQL, but now the environment is