我正在创建asp.net mvc4示例.在此我创建了ID列作为GUID在表格的datacontext.
public class Sample
{
[required]
public Guid ID { get; set; }
[required]
public string FirstName { get; set; }
}
这是实体表
CreateTable(
"dbo.Samples",c => new
{
ID = c.Guid(nullable: false),FirstName = c.String(nullable: false)
})
.PrimaryKey(t => t.ID);
Id通过00000000-0000-0000-0000-000000000000.
如何将newid()设置为GUID以及我必须设置的位置.
解决方法
我建议只使用长时间的ID类型.它与“GUID”相匹配,并具有一定的性能提升.但是,如果要使用GUID,您应该使用
Sequential GUID并将其设置在构造函数中.我也会将ID设为私人设定者：
public class Sample
{
public Sample() {
ID = GuidComb.Generate();
}
[required]
public Guid ID { get; private set; }
[required]
public string FirstName { get; set; }
}
顺序GUID
public static class GuidComb
{
public static Guid Generate()
{
var buffer = Guid.NewGuid().ToByteArray();
var time = new DateTime(0x76c,1,1);
var now = DateTime.Now;
var span = new TimeSpan(now.Ticks - time.Ticks);
var timeOfDay = now.TimeOfDay;
var bytes = BitConverter.GetBytes(span.Days);
var array = BitConverter.GetBytes(
(long)(timeOfDay.TotalMilliseconds / 3.333333));
Array.Reverse(bytes);
Array.Reverse(array);
Array.Copy(bytes,bytes.Length - 2,buffer,buffer.Length - 6,2);
Array.Copy(array,array.Length - 4,buffer.Length - 4,4);
return new Guid(buffer);
}
}
