EF Core可以使用数据注释配置删除行为。

huangapple
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英文:

ef core configure on delete behavior by data annotation

问题

尝试通过数据注解实现外键的删除行为。我尝试了以下方式：

以下是我的模型配置

  1. public class Course
  2. {
  3.     public int CourseId { get; set; }
  4.     public string CourseName { get; set; }
  5.     public int CourseType { get; set; }
  6.     public bool IsActive { get; set; }
  7.     public bool IsDeleted { get; set; }
  8. }
  10. public class Staff
  11. {
  12.     public int StaffId { get; set; }
  13.     public string StaffName { get; set; }
  14.     [Required]
  15.     public int CourseId { get; set; }
  16.     public virtual Course Course { get; set; }
  17.     public bool IsActive { get; set; }
  18.     public bool IsDeleted { get; set; }
  19. }

当进行迁移时，生成了以下代码：

  1. migrationBuilder.CreateTable(
  2.     name: "Staff",
  3.     columns: table => new
  4.     {
  5.         StaffId = table.Column<int>(type: "int", nullable: false)
  6.             .Annotation("SqlServer:Identity", "1, 1"),
  7.         StaffName = table.Column<string>(type: "nvarchar(max)", nullable: false),
  8.         CourseId = table.Column<int>(type: "int", nullable: false),
  9.         IsActive = table.Column<bool>(type: "bit", nullable: false),
  10.         IsDeleted = table.Column<bool>(type: "bit", nullable: false)
  11.     },
  12.     constraints: table =>
  13.     {
  14.         table.PrimaryKey("PK_Staff", x => x.StaffId);
  15.         table.ForeignKey(
  16.             name: "FK_Staff_Courses_CourseId",
  17.             column: x => x.CourseId,
  18.             principalTable: "Courses",
  19.             principalColumn: "CourseId",
  20.             onDelete: ReferentialAction.Cascade);
  21.     });

现在想要更改删除行为（而不是手动更改）为"Required"而不是"Cascade"。我知道可以使用Fluent API 来实现这一点，但不知道是否可以使用数据注解来实现？

英文:

Trying to achieve foreign key on delete behavior by data annotation.
I tried in the following way

Below are my model configuration

  1.  public class Course
  2.     {
  3.         public int CourseId { get; set; }
  4.         public string CourseName { get; set; }
  5.         public int CourseType { get; set; }
  6.         public bool IsActive { get; set; }
  7.         public bool IsDeleted { get; set; }
  8.     }
  10.     public class Staff
  11.     {
  12.         public int StaffId { get; set; }
  13.         public string StaffName { get; set; }
  14.         [Required]
  15.         public int CourseId { get; set; }
  16.         public virtual Course Course { get; set; }
  17.         public bool IsActive { get; set; }
  18.         public bool IsDeleted { get; set; }
  19.     }

When the migration is added it generated below

  1. migrationBuilder.CreateTable(
  2.                 name: &quot;Staff&quot;,
  3.                 columns: table =&gt; new
  4.                 {
  5.                     StaffId = table.Column&lt;int&gt;(type: &quot;int&quot;, nullable: false)
  6.                         .Annotation(&quot;SqlServer:Identity&quot;, &quot;1, 1&quot;),
  7.                     StaffName = table.Column&lt;string&gt;(type: &quot;nvarchar(max)&quot;, nullable: false),
  8.                     CourseId = table.Column&lt;int&gt;(type: &quot;int&quot;, nullable: false),
  9.                     IsActive = table.Column&lt;bool&gt;(type: &quot;bit&quot;, nullable: false),
  10.                     IsDeleted = table.Column&lt;bool&gt;(type: &quot;bit&quot;, nullable: false)
  11.                 },
  12.                 constraints: table =&gt;
  13.                 {
  14.                     table.PrimaryKey(&quot;PK_Staff&quot;, x =&gt; x.StaffId);
  15.                     table.ForeignKey(
  16.                         name: &quot;FK_Staff_Courses_CourseId&quot;,
  17.                         column: x =&gt; x.CourseId,
  18.                         principalTable: &quot;Courses&quot;,
  19.                         principalColumn: &quot;CourseId&quot;,
  20.                         onDelete: ReferentialAction.Cascade);
  21.                 });

Now want to change ondelete behavior (not manually) as required instead of cascade.
I know we can achieve it using fluent API but wondering can we achieve it using data annotation ??

答案1

得分: 1

这在EF Core 7中是可能的，使用DeleteBehaviorAttribute。如果您不使用EF Core 7，则可以使用下面更详细描述的代码 这里。否则，您必须使用FluentAPI。

  1. foreach (var relationship in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
  2. {
  3.     relationship.DeleteBehavior = DeleteBehavior.Restrict;
  4. }
  2. <details>
  3. <summary>英文:</summary>
  5. It&#39;s possible in EF Core 7 with the [DeleteBehaviorAttribute][1]. If you are not in EF Core 7 then you can use this below code described in more detail [here][2]. Otherwise you have to use FluentAPI.
  7.     foreach (var relationship in modelBuilder.Model.GetEntityTypes().SelectMany(e =&gt; e.GetForeignKeys()))
  8.     {
  9.         relationship.DeleteBehavior = DeleteBehavior.Restrict;
  10.     }
  15.   [1]: https://learn.microsoft.com/en-us/ef/core/modeling/relationships/mapping-attributes#deletebehaviorattribute
  16.   [2]: https://stackoverflow.com/questions/49326769/entity-framework-core-delete-cascade-and-required
  18. </details>

huangapple
  • 本文由 发表于 2023年2月24日 00:45:22
  • 转载请务必保留本文链接：https://go.coder-hub.com/75547816.html
  • c#
  • ef-core-2.2
  • entity-framework-core
  • relational-database
  • sql-server
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