如何处理实体框架5 code首先主键 [英] How to Handle Primary Key in Entity Framework 5 Code First
问题描述
在我EF5 code-首款车型,新纪录创造更好的工作,如果数据库设置主键。我使用的是GUID的主键,如果 DatabaseGeneratedOption.Identity
设置,SQL Server将始终创建唯一标识符
。
然而,这会导致问题,当我试图最初种子数据库。如果我在种方法中设置的GUID,SQL Server将重写它。如果我没有设置的GUID,每次都遇到了新的纪录。什么是推荐的解决方案使用pre-的GUID种子数据库,并保持 DatabaseGeneratedOption.Identity
我的正常操作设置?
例类模型:
[重点]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)
公众的Guid标识{搞定;组; }
公共RecordName {搞定;组; }
公众的DateTime?创建{搞定;组; }
公众的DateTime?更新{搞定;组; }
例如种子的方法:
VAR纪录=新记录()
{
ID =新的GUID(3B80725E-9550-4933-807F-C2FAA0942225),
RecordName =新纪录,
创建= DateTime.UtcNow,
更新= DateTime.UtcNow,
};
context.Record.AddOrUpdate(记录);
context.SaveChanges();
AddOrUpdate有一个覆盖,它允许您指定密钥
所以,你需要用自然键提供方法:
context.Record.AddOrUpdate(C => c.RecordName,新记录()
{
RecordName =新纪录,
创建= DateTime.UtcNow,
更新= DateTime.UtcNow,
})
In my EF5 code-first models, creation of new records works better if the database sets the primary key. I am using a Guid for primary key and if DatabaseGeneratedOption.Identity
is set, SQL Server will always create the uniqueidentifier
.
However, this causes issues when I am trying to initially seed the database. If I set the Guid in my seed method, SQL Server overrides it. If I don't set the Guid, I get a new record every time. What is a recommended solution to seed the database using pre-set Guids and keep DatabaseGeneratedOption.Identity
set for my normal operations?
Example class model:
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid Id { get; set; }
public RecordName { get; set; }
public DateTime? Created { get; set; }
public DateTime? Updated { get; set; }
Example seed method:
var record = new Record()
{
Id = new Guid("3B80725E-9550-4933-807F-C2FAA0942225"),
RecordName = "New Record",
Created = DateTime.UtcNow,
Updated = DateTime.UtcNow,
};
context.Record.AddOrUpdate(record);
context.SaveChanges();
AddOrUpdate has an override that allows you to specify the key
From MSDN
So you need to supply the method with the natural key:
context.Record.AddOrUpdate(c => c.RecordName, new Record()
{
RecordName = "New Record",
Created = DateTime.UtcNow,
Updated = DateTime.UtcNow,
})
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