实体框架不会更新mySql中计算密钥的自动增量字段 [英] Entity Framework does not update an auto-increment field of a computed key in mySql

问题描述

我正在尝试使用实体框架保存实体，尽管EF不更新自动递增字段

  public类地址
 {
 public int Id {get;组; } 
 public int DatacenterId {get;组; } 
 public virtual Datacenter Datacenter {get;组; } 
} 
 
 public class AddressMapping：EntityTypeConfiguration< Address> 
 {
 public AddressMapping（）
 {
 this.HasKey（k => new {k.Id，k.DatacenterId}）; 
 this.HasRequired（itr => itr.Datacenter）
 .WithMany（）
 .HasForeignKey（fk => fk.DatacenterId）; 
 
 this.Property（p => p.Id）
 .HasDatabaseGeneratedOption（DatabaseGeneratedOption.Identity）; 
} 
} 
 
使用（var context = new MyContext（））
 {
 var address = new Address（）; //初始化并设置所有值。包含FK 
 context.Address.Add（address）; 
 context.SaveChanges（）; 
 
 //address.Id仍然是0 
} 
  

我从mySql中分析了以下命令：

  INSERT INTO'address`（
`Id`，
 `DatacenterId`，
）VALUES（
 0，
 1，
）
  

解决方案

我已经改变了映射命令的顺序，它正在工作。我不知道EF映射命令可以改变映射结果。

  public class AddressMapping：EntityTypeConfiguration< Address> 
 {
 public AddressMapping（）
 {
 this.Property（p => p.Id）
 .HasDatabaseGeneratedOption（DatabaseGeneratedOption.Identity）; 
 
 this.HasKey（k => new {k.Id，k.DatacenterId}）; 
 
 this.HasRequired（itr => itr.Datacenter）
 .WithMany（）
 .HasForeignKey（fk => fk.DatacenterId）; 
} 
} 
  

最后它生成了正确的sql命令： （
`DatacenterId`，
）VALUES（
1，
）;
SELECT
`Id`
FROM
`address`
WHERE
row_count（）> 0 AND`Id` = last_insert_id（）AND'DatacenterId` = 1

I'm trying to save an entity using entityframework, although the EF is not update the auto-increment field

public class Address
{
    public int Id { get; set; }
    public int DatacenterId { get; set; }
    public virtual Datacenter Datacenter { get; set; }
}

public class AddressMapping : EntityTypeConfiguration<Address>
{
    public AddressMapping()
    {
        this.HasKey(k => new { k.Id, k.DatacenterId });
        this.HasRequired(itr => itr.Datacenter)
            .WithMany()
            .HasForeignKey(fk => fk.DatacenterId);

        this.Property(p => p.Id)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
    }
}

using (var context = new MyContext())
{
    var address = new Address(); //Initialize and set all values. Include the FK
    context.Address.Add(address);
    context.SaveChanges();

    //address.Id is still 0
}

I profiled the following command from mySql:

INSERT INTO `address`(
    `Id`, 
    `DatacenterId`, 
)VALUES(
    0, 
    1, 
)

解决方案

I've changed the order of mapping commands and it is working. I didn't know the EF mapping commands could change the mapping result.

public class AddressMapping : EntityTypeConfiguration<Address>
{
    public AddressMapping()
    {
        this.Property(p => p.Id)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);

        this.HasKey(k => new { k.Id, k.DatacenterId });

        this.HasRequired(itr => itr.Datacenter)
            .WithMany()
            .HasForeignKey(fk => fk.DatacenterId);
    }
}

And finally it generated the correct sql command:

INSERT INTO `address`(
    `DatacenterId`, 
)VALUES(
    1, 
);
SELECT
    `Id`
FROM 
    `address`
WHERE  
     row_count() > 0 AND `Id` = last_insert_id() AND `DatacenterId` = 1

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