EF是否可以使用阴影属性创建Mutli-column索引? [英] EF can you make a Mutli-column Index using shadow properties?
问题描述
我正在尝试使用shadow属性创建多列唯一索引。我知道我可以通过添加一个属性来解决此问题,但我想看看是否有可能保持模型清洁。
I'm trying to create a multi-column unique index using a shadow property. I know I can solve this problem with just adding a property, but I would like to see if this is possible in a way to keep my model clean.
创建一个多列索引在Fluent API中具有以下选项:
To create a multi-column index you have the following option in Fluent API:
modelBuilder.Entity<AlbumTrack>().HasIndex(t => new { t.TrackNumber, t.AlbumId).IsUnique();
但是我不想用额外的 AlbumId
属性,因此想使用shadow属性,对于单个列,其工作方式如下:
But I don't want to clutter my model with an extra AlbumId
property and thus would like to use a shadow property, for a single column this works as followed:
modelBuilder.Entity<AlbumTrack>().HasIndex(t => EF.Property<int>(t,"AlbumId")).IsUnique();
我尝试了以下操作:
modelBuilder.Entity<AlbumTrack>()
.HasIndex(t => new { t.TrackNumber, EF.Property<int>(t,"AlbumId")})
.IsUnique();
但是我的IDE抛出以下错误:
However my IDE throws the following error:
无效的匿名类型成员声明符。匿名类型成员必须声明为具有成员分配,简单名称或成员访问权限。
Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or member access.
任何人都知道如何使用
编辑:各种语法错误。
推荐答案
有可能。您可以简单地将 HasIndex
重载与 params string [] propertyNames
一起使用。
It's possible. You can simply use the HasIndex
overload with params string[] propertyNames
.
首先确保定义了shadow属性:
First make sure the shadow property is defined:
modelBuilder.Entity<AlbumTrack>()
.Property<int>("AlbumId");
然后定义索引:
modelBuilder.Entity<AlbumTrack>()
.HasIndex("TrackNumber", "AlbumId")
.IsUnique();
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