当只有 model1 引用其他模型时，如何使用 fluent API 添加外键？

Question

如何使用 fluent api 添加外键？

例如

模型 1

身份证号，姓名，model2.id

模型2

身份证、姓名

我读过有关 HasOne Method 建立一对一关系的内容，但此示例显示模型 1 仅引用模型 2。

Answer 1

我在下面创建了一个demo，model1是Employee，model2是Department，Employee引用了Department

型号：

public class Employee
{
    [Key]
    public int Id { get; set; }
    public string Name { get; set; }

    public int DepartmentId { get; set; }
    public Department Department { get; set; }
}

public class Department
{
    [Key]
    public int Id { get; set; }
    public string Name { get; set; }

}

dcContext:

protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);

        builder.Entity<Employee>()
        .HasOne(e => e.Department)
        .WithOne()
        .HasForeignKey<Employee>(e => e.DepartmentId);

    }

结果：

migrationBuilder.CreateTable(
            name: "Employees",
            columns: table => new
            {
                Id = table.Column<int>(nullable: false)
                    .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn),
                Name = table.Column<string>(nullable: true),
                DepartmentId = table.Column<int>(nullable: false)
            },
            constraints: table =>
            {
                table.PrimaryKey("PK_Employees", x => x.Id);
                table.ForeignKey(
                    name: "FK_Employees_Department_DepartmentId",
                    column: x => x.DepartmentId,
                    principalTable: "Department",
                    principalColumn: "Id",
                    onDelete: ReferentialAction.Cascade);
            })

当只有 model1 引用其他模型时，如何使用 fluent API 添加外键？

How to add foreign key using fluent API when only model1 has reference to other model?

c#

asp.net-core

ef-core-2.2