code first 更新字段

 protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AddColumn<string>(
                name: "ResponsiblePerson",
                table: "AppYWProducts",
                nullable: true);
            migrationBuilder.AddColumn<bool>(
               name: "CheckLimited",
               table: "AppYWProducts",
               nullable: false);
        }

        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.DropColumn(
                name: "ResponsiblePerson",
                table: "AppYWProducts");
            migrationBuilder.DropColumn(
              name: "CheckLimited",
              table: "AppYWProducts");
        }