C# C实体框架核心.Include()问题
实体框架的Include函数有问题 使用的框架:.NET Core 3.1和实体框架Core 3.1.5 这些是我的实体C# C实体框架核心.Include()问题,c#,entity-framework-core-3.1,C#,Entity Framework Core 3.1,实体框架的Include函数有问题 使用的框架:.NET Core 3.1和实体框架Core 3.1.5 这些是我的实体 public class EntityA { [Key] [DatabaseGenerated(DatabaseGeneratedOption.Identity)] public int Id { get; set; } [Required] [Index(IsUnique = true)] public int En
public class EntityA
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Required]
[Index(IsUnique = true)]
public int EntityBId { get; set; }
[ForeignKey("EntityBId")]
public EntityB EntityB { get; set; }
[DefaultValue(false)]
public bool IsConfirmed { get; set; }
}
public class EntityB
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
[Required]
public string Title { get; set; }
public string Description { get; set; }
}
所以我启动这个查询:
public ICollection<EntityA> GetAll(string contextName)
{
DbContext context = GetContext(contextName);
ICollection<EntityA> collection = context.EntityAs
.Include(j => j.EntityB)
.Where(x => x.IsConfirmed)
.ToList();
return collection;
}
private DbContext GetContext(string contextName)
{
string contextDbConnectionString = _secretsRepository.GetDbConnectionString(contextName);
DbContextOptionsBuilder<DbContext> optionsBuilder = new DbContextOptionsBuilder<DbContext>();
optionsBuilder.UseSqlServer(contextDbConnectionString);
return new DbContext(optionsBuilder.Options);
}
我不明白的是,Includej=>j.EntityB为什么没有返回正确值的EntityB字段当我试图用所提供的实体构建数据模型时,在Index属性处遇到了编译错误
[Required]
[Index(IsUnique = true)]
public int EntityBId { get; set; }
原来EntityFramework6库曾经具有该属性,但问题涉及EntityFrameworkCore。所以我只是删除了Index属性,并将其移动到OnModelCreating方法以模拟类似的行为
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<EntityA>().HasIndex(u => u.EntityBId).IsUnique();
}
希望它有助于解决您的问题。尝试将EntityB标记为虚拟,因此公共虚拟EntityB EntityB{get;set}请检查生成的SQL以开始。它包括实体B吗?@MindSwipe我按你说的做了尝试,但什么都没有changed@TomTom我已经看过了,但生成的查询结果如下:从[EntityAs]中选择[p].[Id],[p].[IsConfiged],[p].[EntityBId]作为[p],此处[p].[IsConfiged]=CAST1作为bitOk,因此EfCore没有生成SQL。您的DbContext没有正确注册元数据,因此永远不会解析关系。查看如何正确配置DbContext。谢谢,这解决了我的问题,我的问题是由于实体框架6库和实体框架核心库
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<EntityA>().HasIndex(u => u.EntityBId).IsUnique();
}
SELECT [e].[Id], [e].[EntityBId], [e].[IsConfirmed], [e0].[Id], [e0].[Description],
[e0].[Title]
FROM [EntityAs] AS [e]
INNER JOIN [EntityBs] AS [e0] ON [e].[EntityBId] = [e0].[Id]
WHERE [e].[IsConfirmed] = CAST(1 AS bit)