EF Core 主键和数据库迁移以及注意事项

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How are you doing?
		Great! 
		How are you doing?
Not to bad,thanks!
		Take it easy~
		
		
what do you do for a living?//靠什么生活
				I'm a teacher.
Oh，really,what do you teach?
                I’m math teacher at Carson College.
		

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using TestDbContext ctx = new TestDbContext();
Console.WriteLine("****1*****");
Author a1 = new Author { Name = "杨中科" };
Console.WriteLine($"Add前，Id={a1.Id}");
ctx.Authors.Add(a1);
Console.WriteLine($"Add后，保存前，Id={a1.Id}");
await ctx.SaveChangesAsync();
Console.WriteLine($"保存后，Id={a1.Id}");
Console.WriteLine("****2*****");
Author a2 = new Author { Name = "Zack Yang" };
a2.Id = Guid.NewGuid();
Console.WriteLine($"保存前，Id={a2.Id}");
ctx.Authors.Add(a2);
await ctx.SaveChangesAsync();
Console.WriteLine($"保存前，Id={a2.Id}");

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Add-Migration

Update-datebase

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public partial class Init : Migration
    {
        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.CreateTable(
                name: "Authors",
                columns: table => new
                {
                    Id = table.Column<Guid>(type: "uniqueidentifier", nullable: false),
                    Name = table.Column<string>(type: "nvarchar(max)", nullable: false)
                },
                constraints: table =>
                {
                    table.PrimaryKey("PK_Authors", x => x.Id);
                });
        }

        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.DropTable(
                name: "Authors");
        }
    }

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 	[DbContext(typeof(TestDbContext))]//表示作用那个DbContext（上下文）
    [Migration("20220105064712_Init")]//对应的版本号
    partial class Init
    {
    }