实体框架7:生成无效的列名称

时间:2016-04-13 00:35:03

标签: c# entity-framework-core

使用EF 7:1.0.0-rc1-final,

我在使用数据库第一种方法正确生成查询时遇到问题 - 使用ef脚手架生成DbContext中列出的一些模型属性 - 因为表包含大量列我只需要一些为webapi工作,因此它们是列映射

我有3个实体,品牌,活动和会话

品牌包含许多事件和事件包含许多会话

我的模特:

[Table("tblBranding")]
public class Brand 
{
    [Key]
    [Column("brandingId")]
    public int BrandId { get; set; }
    [Column("BrandingActive")]
    public bool Active { get; set; }
    [JsonIgnore]
    [Column("DeadBrand")]        
    public bool DeadBrand { get; set; }
    [Column("BrandingSiteTitle")]
    public string Name { get; set; }

    //navigation properties
    public virtual ICollection<Event> Events { get; set; }
}

[Table("tblEvents")]
public class Event
{           
    public int EventId { get; set; }
    [Column("eventActive")]
    public bool Active { get; set; }
    [Column("eventName")]
    public string Name { get; set; }        
    public DateTime EventCloseDate {get;set;}        
    public int PaxAllocationLimit { get; set; }

    //navigation properties             
    [JsonIgnore]        
    [Column("brandingId")]

    public virtual int BrandId { get; set; }
    [JsonIgnore]
    [ForeignKey("BrandId")]
    public virtual Brand Brand { get; set; }
    public virtual ICollection<Session> Sessions { get; set; }
}

[Table("tblEventsDates")]
public class Session
{       
    [Column("EventDateID")]
    public int SessionId { get; set; }
    [Column("EventDateName")]
    public string Name { get; set; }               
    [Column("EventDate")]
    public DateTime SessionDate { get; set; }        
    [Column("EventDateTime")]
    public DateTime SessionTime { get; set; }
    [Column("EventDateMinutes")]
    public decimal? SessionDurationInMinutes { get; set; }
    [Column("EventDateArrival")]
    public DateTime? ArrivalTime { get; set; }
    [Column("EventCapacity")]
    public int SessionCapacity { get; set; }

    //navigation properties        
    [JsonIgnore]        
    public virtual int EventId { get; set; }
    [JsonIgnore]        
    public virtual Event Event { get; set; }            
}

我的DbContext

protected override void OnModelCreating(ModelBuilder modelBuilder) 
{       
    modelBuilder.Entity<Event>()
        .HasOne(e => e.Brand)
        .WithMany(b => b.Events).HasForeignKey(e=>e.BrandId);

    modelBuilder.Entity<Event>()
        .HasMany(s => s.Sessions)
        .WithOne(e => e.Event).HasForeignKey(s => s.EventId);

    modelBuilder.Entity<Event>(entity=> {
        entity.Property(e => e.EventId).HasColumnName("EventID");
        entity.HasKey(e => new{ e.EventId, e.EventCloseDate});
        entity.HasIndex(e => e.EventId).HasName("For Full Text Indexing").IsUnique();
        entity.Property(e => e.Active).HasDefaultValue(false);
        entity.Property(e => e.EventCloseDate)
            .HasColumnType("datetime")
            .HasDefaultValueSql("'1/1/2038'");
        entity.Property(e => e.Name).HasMaxLength(1024);
        entity.Property(e => e.PaxAllocationLimit).HasDefaultValue(10000);
    });

    modelBuilder.Entity<Brand>(entity => {
        entity.HasKey(e => e.BrandId);                

        entity.Property(e => e.Active).HasDefaultValue(false);               

        entity.Property(e => e.Name)
            .IsRequired()
            .HasMaxLength(150)
            .HasColumnType("varchar");                
    });

    modelBuilder.Entity<Session>(entity => {
        entity.HasKey(e => e.SessionId);

        entity.Property(e=>e.Name)
          .HasMaxLength(250)
            .HasColumnType("varchar")
            .HasDefaultValue("");

        entity.Property(e => e.SessionDurationInMinutes)
            .HasColumnType("numeric")
            .HasDefaultValue(0m);                
        });
    }

    public virtual DbSet<Brand> Brands { get; set; }
    public virtual DbSet<Event> Events { get; set; }        
    public virtual DbSet<Session> Sessions { get; set; }
}

我使用该项目作为webapi,当我调用Brands时,它会生成以下SQL:

SELECT [e].[brandingId], [e].[BrandingActive], [e].[DeadBrand], [e].[BrandingSiteTitle]
FROM [tblBranding] AS [e]
WHERE [e].[BrandingActive] = 1
ORDER BY [e].[BrandingSiteTitle], [e].[brandingId]
Microsoft.Data.Entity.Storage.Internal.RelationalCommandBuilderFactory: Information: Executed DbCommand (75ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
SELECT [t].[EventId], [t].[EventCloseDate], [t].[eventActive], [t].[brandingId], [t].[EventId1], [t].[eventName], [t].[PaxAllocationLimit]
FROM [tblEvents] AS [t]
INNER JOIN (
    SELECT DISTINCT [e].[BrandingSiteTitle], [e].[brandingId]
    FROM [tblBranding] AS [e]
    WHERE [e].[BrandingActive] = 1
) AS [e] ON [t].[brandingId] = [e].[brandingId]
ORDER BY [e].[BrandingSiteTitle], [e].[brandingId]

其中[t]。[EventId1]列名无效 请注意,如果我在DbContext中注释掉以下代码 - 此错误消失并且查询生成正确:

modelBuilder.Entity<Event>()
            .HasMany(s => s.Sessions)
            .WithOne(e => e.Event).HasForeignKey(s => s.EventId);

我尝试添加[ForeignKey],[InverseProperty]属性,同时“摆弄”&#39; - 它似乎没什么区别

我还尝试明确添加列名here

我不知道还有什么可以尝试 - 只有当我在FluidUI中定义与Sessions的关系时才开始发生 - 建议?

2 个答案:

答案 0 :(得分:4)

只是为了好玩。尝试制作这个数据库。我删除了很多“杂乱”的EF就像ASP.NET MVC一样,基于约定优于配置的概念。

您最多完成了2次配置(属性和/或FluentApi),而实际上您可以完成0次。

以下是一些关于约定的基本规则(约定对触发器不区分大小写。)

  • 要制作密钥(也称为主键),您必须将其命名为Id或[classname] Id
  • 要创建一个外键,你可以将它命名为[foreighClassName(partA)] Id(如果你添加下一个,则不需要这个(而且你可以同时使用两个,但是名称必须相同)(partA) )
  • 要访问外部“body”对象,只需添加类似public Brand Brand { get; set; }类型的属性,如果只有一个“链接”,则名称不重要。
  • 在初级端,您可能希望使用某种集合来包装所有子项,并且是public ICollection<Event> Events { get; set; }是可行的方法。有人可能会问IEnumerableIList(以这种方式来考虑,IEnumerable无法.Add(),因此它或多或少是只读的。IList好吧,它会做得越来越多,如果它不适合做那些不能翻译的东西,那将是一个不错的选择。所以在中间我们有ICollection

使用虚拟关键字时?好吧在EF7中你不使用它,因为它用于启用延迟加载,而EF7没有(还),我们不知道它们是否要添加它。 Github EF7 feature request lacking lazyload

为什么要删除[JsonIgnore]属性?切勿将实体模型发送给客户端。创建一个合适的DTO(在ASP.NET MVC中通常称为模型)

记得做迁移,并且(为了好玩)首先尝试在FluentAPI中没有任何“硬编码”要求,并查看将看到PK / FK完成的迁移代码,为您添加索引和其他几个bob和别针

public class Brand 
{
    public int Id { get; set; }
    public bool Active { get; set; }
    public bool DeadBrand { get; set; }
    public string Name { get; set; }

    //navigation properties
    public ICollection<Event> Events { get; set; }
}

public class Event
{           
    public int Id { get; set; }
    public bool Active { get; set; }
    public string Name { get; set; }        
    public DateTime EventCloseDate {get;set;}        
    public int PaxAllocationLimit { get; set; }

    //navigation properties             
    public Brand Brand { get; set; }
    public ICollection<Session> Sessions { get; set; }
}

public class Session
{       
    public int Id { get; set; }
    public string Name { get; set; }   
    //Datetime contains date and time        
    public DateTime Time { get; set; } 
    //TimeSpan is for duration, allowing access to seconds, minutes, hours etc.
    public TimeSpan Duration { get; set; } 
    public DateTime? ArrivalTime { get; set; }
    public int SessionCapacity { get; set; }

    //navigation properties        
    public Event Event { get; set; }            
}

上下文类

class DbContex{

    public virtual DbSet<Brand> Brands { get; set; }
    public virtual DbSet<Event> Events { get; set; }        
    public virtual DbSet<Session> Sessions { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder) 
    {       
    //Personally I would not have many requirements in the database unless I              
    //was completely sure it had to be that way.
    //They will ALWAYS bite you in the ass in the long run.

        modelBuilder.Entity<Event>(entity=> {
            entity.Property(e => e.Active).HasDefaultValue(false);
            entity.Property(e => e.EventCloseDate)
                .HasColumnType("datetime")
                .HasDefaultValueSql("'1/1/2038'");
            entity.Property(e => e.Name).HasMaxLength(1024);
            entity.Property(e => e.PaxAllocationLimit).HasDefaultValue(10000);
        });

        modelBuilder.Entity<Brand>(entity => {
            entity.Property(e => e.Active).HasDefaultValue(false);    
            entity.Property(e => e.Name)
                .IsRequired()
                .HasMaxLength(150)
                .HasColumnType("varchar");                
        });

        modelBuilder.Entity<Session>(entity => {
            entity.Property(e=>e.Name)
                .HasMaxLength(250)
                .HasColumnType("varchar")
                .HasDefaultValue("");    
            entity.Property(e => e.SessionDurationInMinutes)
                .HasColumnType("numeric")
                .HasDefaultValue(0m);                
            });
        }
    }
}

答案 1 :(得分:1)

回答我自己的问题 - 好像它可能是EF 7 1.0.0-RC1中的一个错误

在DbContext中的Event的实体属性

 modelBuilder.Entity<Event>(entity=> {
    entity.Property(e => e.EventId).HasColumnName("EventID");
    entity.HasKey(e => new{ e.EventId, e.EventCloseDate});
    entity.HasIndex(e => e.EventId).HasName("For Full Text Indexing").IsUnique();
    entity.Property(e => e.Active).HasDefaultValue(false);
    entity.Property(e => e.EventCloseDate)
        .HasColumnType("datetime")
        .HasDefaultValueSql("'1/1/2038'");
    entity.Property(e => e.Name).HasMaxLength(1024);
    entity.Property(e => e.PaxAllocationLimit).HasDefaultValue(10000);
});

请注意,它有2个键 - 这是从脚手架生成的,该表有一个复合主键

但是对于我对API的要求,我只需要一个主要标识符 - 删除复合键修复了无效列生成错误

更新代码:

modelBuilder.Entity<Event>(entity=> {
    entity.Property(e => e.EventId).HasColumnName("EventID");
    entity.HasKey(e => e.EventId);
    entity.HasIndex(e => e.EventId).HasName("For Full Text Indexing").IsUnique();
    entity.Property(e => e.Active).HasDefaultValue(false);
    entity.Property(e => e.EventCloseDate)
        .HasColumnType("datetime")
        .HasDefaultValueSql("'1/1/2038'");
    entity.Property(e => e.Name).HasMaxLength(1024);
    entity.Property(e => e.PaxAllocationLimit).HasDefaultValue(10000);
});