设置用流利的API唯一约束？ [英] Setting unique Constraint with fluent API?

问题描述

我试图用code构建一个EF实体首先，用流利的API一个 EntityTypeConfiguration 。创建主键很容易，但并非如此具有唯一约束。我看到所建议的这个执行本地SQL命令旧文章，但似乎打败的目的。这可能与EF6？

I'm trying to build an EF Entity with Code First, and an EntityTypeConfiguration using fluent API. creating primary keys is easy but not so with a Unique Constraint. I was seeing old posts that suggested executing native SQL commands for this, but that seem to defeat the purpose. is this possible with EF6?

推荐答案

在 EF6.1 起，您可以使用 IndexAnnotation（）来加移民索引您流畅的API中。

On EF6.1 onwards, you can use IndexAnnotation() to add indexes for migration in your fluent API.

<一个href=\"http://msdn.microsoft.com/en-us/data/jj591617.aspx#PropertyIndex\">http://msdn.microsoft.com/en-us/data/jj591617.aspx#PropertyIndex

您必须添加引用：

using System.Data.Entity.Infrastructure.Annotations;

Basic范例

下面是一个简单的使用量，增加对 User.FirstName 属性的索引

Here is a simple usage, adding an index on the User.FirstName property

modelBuilder 
    .Entity<User>() 
    .Property(t => t.FirstName) 
    .HasColumnAnnotation(IndexAnnotation.AnnotationName, new IndexAnnotation(new IndexAttribute()));

实例：

下面是一个更现实的例子。它在多个属性将唯一索引： User.FirstName 和 User.LastName ，与索引名IX_FIrstNameLastName

Here is a more realistic example. It adds a unique index on multiple properties: User.FirstName and User.LastName, with an index name "IX_FIrstNameLastName"

modelBuilder 
    .Entity<User>() 
    .Property(t => t.FirstName) 
    .IsRequired()
    .HasMaxLength(60)
    .HasColumnAnnotation(
        IndexAnnotation.AnnotationName, 
        new IndexAnnotation(
            new IndexAttribute("IX_FirstNameLastName", 1) { IsUnique = true }));

modelBuilder 
    .Entity<User>() 
    .Property(t => t.LastName) 
    .IsRequired()
    .HasMaxLength(60)
    .HasColumnAnnotation(
        IndexAnnotation.AnnotationName, 
        new IndexAnnotation(
            new IndexAttribute("IX_FirstNameLastName", 2) { IsUnique = true }));

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