entity-framework-core

问题 There are many questions about seeding many-to-many relationships in Entity Framework. However, most of them are extremely old, and many-to-many behavior has changed significantly in EFCore5. The official docs recommend overriding OnModelCreating to implement ModelBuilder.Entity<>.HasData() . However, with the new many-to-many behavior (without explicit mappings), I can find no clear path to seed the intermediate tables. To use the example of this tutorial, the BookCategories class is now

问题 There are many questions about seeding many-to-many relationships in Entity Framework. However, most of them are extremely old, and many-to-many behavior has changed significantly in EFCore5. The official docs recommend overriding OnModelCreating to implement ModelBuilder.Entity<>.HasData() . However, with the new many-to-many behavior (without explicit mappings), I can find no clear path to seed the intermediate tables. To use the example of this tutorial, the BookCategories class is now

问题 I created a new project with the XAF Blazor 20.2.3 wizard and upgraded the EFCore packages to 5.0. In PM I ran Install-Package Microsoft.EntityFrameworkCore.Tools However when I run add-migration initial I get Unable to create an object of type 'ExamBuddyEFCoreDbContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728 I have looked at the link but I don't think it applies to the xaf Blazor app. I tried commenting out the Database

问题 Repost model class: public class TransactionDayReport { public Decimal TotalAmount { get; set; } public ICollection<TransactionResponse> TransactionResponses { get; set; } = null!; } This is my repository method public async Task<IEnumerable<Transaction>> SearchTransactionAsync(SearchTransaction search) { var query = _context.Transactions .Include(t => t.Branch) .Include(t => t.Customer) .AsQueryable(); if (search.CIN != null) query = query.Where(t => t.Customer.CIN.Contains(search.CIN)); if

问题 Repost model class: public class TransactionDayReport { public Decimal TotalAmount { get; set; } public ICollection<TransactionResponse> TransactionResponses { get; set; } = null!; } This is my repository method public async Task<IEnumerable<Transaction>> SearchTransactionAsync(SearchTransaction search) { var query = _context.Transactions .Include(t => t.Branch) .Include(t => t.Customer) .AsQueryable(); if (search.CIN != null) query = query.Where(t => t.Customer.CIN.Contains(search.CIN)); if

问题 My project is using EF Core 3.1, and targeting Azure Cosmos as the database. I have an entity like this: public class MyEntity { public IEnumerable<string> Names {get;set;} ... other fields } That I would like to end up in a Cosmos document like this: { "Names": ["Name1", "Name2"] } With the entity as is ( IEnumerable<string> ) I get the error: The property 'MyEntity.Names' could not be mapped, because it is of type 'IEnumerable' which is not a supported primitive type or a valid entity type.

问题 I am trying to execute a linq query to get all employes that have some specific skills. search.skills is a list of strings with some skills and I want to retrieve all the user which have all those skills (And condition). In my where clause on employees, exp.Skills is ICollection and expSkill.SkillName is the skill name .Where( emp => search.Skills.All( searchSkill => emp.Experiences.Select(exp => exp.Skills).SelectMany(x => x).Select(expSkill => expSkill.SkillName).Contains(searchSkill) ))

问题 I am trying to execute a linq query to get all employes that have some specific skills. search.skills is a list of strings with some skills and I want to retrieve all the user which have all those skills (And condition). In my where clause on employees, exp.Skills is ICollection and expSkill.SkillName is the skill name .Where( emp => search.Skills.All( searchSkill => emp.Experiences.Select(exp => exp.Skills).SelectMany(x => x).Select(expSkill => expSkill.SkillName).Contains(searchSkill) ))

问题 I have a model which is used for managing friend relationships. It looks as follows: public class Relationship { [Required] public User User { get; set; } [Required] public User Friend { get; set; } [Required] public DateTimeOffset RelationshipInitializationDate { get; set; } } Users will have multiple records for their ID and there will be multiple records with the same FriendID so defining either of these as a key is a no-go. I would like the key to be a composite between User and Friend

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