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我嘗試使用ASP.Net 5與Entity Framework 7和SQLite，並且發現了一個奇怪的遷移行爲。EF7使用SQLite生成錯誤的遷移
我提取了Visual Studio 2015並創建了一個模板爲「ASP.NET 5 Template Web Application」的新項目。
在那之後我刪除dependecy
"EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final"
而且增加了兩個依賴，以及比所謂的恢復包。
"EntityFramework.Sqlite": "7.0.0-rc1-final",
"Microsoft.Data.Sqlite": "1.0.0-rc1-final"
就像那個
"dependencies": {
"EntityFramework.Commands": "7.0.0-rc1-final",
"EntityFramework.Sqlite": "7.0.0-rc1-final",
"Microsoft.Data.Sqlite": "1.0.0-rc1-final",
"Microsoft.AspNet.Authentication.Cookies": "1.0.0-rc1-final",
"Microsoft.AspNet.Diagnostics.Entity": "7.0.0-rc1-final",
"Microsoft.AspNet.Identity.EntityFramework": "3.0.0-rc1-final",
"Microsoft.AspNet.IISPlatformHandler": "1.0.0-rc1-final",
"Microsoft.AspNet.Mvc": "6.0.0-rc1-final",
"Microsoft.AspNet.Mvc.TagHelpers": "6.0.0-rc1-final",
"Microsoft.AspNet.Server.Kestrel": "1.0.0-rc1-final",
"Microsoft.AspNet.StaticFiles": "1.0.0-rc1-final",
"Microsoft.AspNet.Tooling.Razor": "1.0.0-rc1-final",
"Microsoft.Extensions.CodeGenerators.Mvc": "1.0.0-rc1-final",
"Microsoft.Extensions.Configuration.FileProviderExtensions": "1.0.0-rc1-final",
"Microsoft.Extensions.Configuration.Json": "1.0.0-rc1-final",
"Microsoft.Extensions.Configuration.UserSecrets": "1.0.0-rc1-final",
"Microsoft.Extensions.Logging": "1.0.0-rc1-final",
"Microsoft.Extensions.Logging.Console": "1.0.0-rc1-final",
"Microsoft.Extensions.Logging.Debug": "1.0.0-rc1-final",
"Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0-rc1-final"
}
接下來我去Startup.cs和更改的功能ConfigurationServices像
public void ConfigureServices(IServiceCollection services)
{
// Add framework services.
var dbFilePath = Path.Combine(PlatformServices.Default.Application.ApplicationBasePath, "test.db");
services.AddEntityFramework()
.AddSqlite()
.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlite("Filename=" + dbFilePath));
System.Console.WriteLine("Use DB file:" + dbFilePath);
services.AddIdentity<ApplicationUser, IdentityRole>()
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();
services.AddMvc();
// Add application services.
services.AddTransient<IEmailSender, AuthMessageSender>();
services.AddTransient<ISmsSender, AuthMessageSender>();
services.AddInstance<IConfigurationRoot>(Configuration);
}
然後，我從文件夾「遷移」刪除所有文件和內置的解決方案。 所有已準備好創建遷移。 我跑項目文件夾和跨下一個命令的git bash下
[email protected] /d/dev/testMVC
$ dnx ef migrations add firstMigration
Use DB file:D:\dev\testMVC\test.db
Done. To undo this action, use 'ef migrations remove'
和
$ dnx ef database update
Use DB file:D:\dev\testMVC\test.db
Applying migration '20160304130532_firstMigration'.
Done.
OK，我看到了一個數據庫文件和文件夾中的「遷移」，它看起來像好。 我猜想下一次生成的遷移將是空的，而不會更改對象模型。 我試圖做到這一點，並進入下一個命令：
$ dnx ef migrations add testMigration
Use DB file:D:\dev\testMVC\test.db
Done. To undo this action, use 'ef migrations remove'
我去看了產生遷移類，我看到這樣的代碼：
protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.DropForeignKey(name: "FK_IdentityRoleClaim<string>_IdentityRole_RoleId", table: "AspNetRoleClaims");
migrationBuilder.DropForeignKey(name: "FK_IdentityUserClaim<string>_ApplicationUser_UserId", table: "AspNetUserClaims");
migrationBuilder.DropForeignKey(name: "FK_IdentityUserLogin<string>_ApplicationUser_UserId", table: "AspNetUserLogins");
migrationBuilder.DropForeignKey(name: "FK_IdentityUserRole<string>_IdentityRole_RoleId", table: "AspNetUserRoles");
migrationBuilder.DropForeignKey(name: "FK_IdentityUserRole<string>_ApplicationUser_UserId", table: "AspNetUserRoles");
migrationBuilder.AddForeignKey(
name: "FK_IdentityRoleClaim<string>_IdentityRole_RoleId",
table: "AspNetRoleClaims",
column: "RoleId",
principalTable: "AspNetRoles",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
migrationBuilder.AddForeignKey(
name: "FK_IdentityUserClaim<string>_ApplicationUser_UserId",
table: "AspNetUserClaims",
column: "UserId",
principalTable: "AspNetUsers",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
migrationBuilder.AddForeignKey(
name: "FK_IdentityUserLogin<string>_ApplicationUser_UserId",
table: "AspNetUserLogins",
column: "UserId",
principalTable: "AspNetUsers",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
migrationBuilder.AddForeignKey(
name: "FK_IdentityUserRole<string>_IdentityRole_RoleId",
table: "AspNetUserRoles",
column: "RoleId",
principalTable: "AspNetRoles",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
migrationBuilder.AddForeignKey(
name: "FK_IdentityUserRole<string>_ApplicationUser_UserId",
table: "AspNetUserRoles",
column: "UserId",
principalTable: "AspNetUsers",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
}
protected override void Down(MigrationBuilder migrationBuilder)
{
...
}
如果我嘗試應用這種遷移，趕上下一個錯誤消息：
$ dnx ef database update
Use DB file:D:\dev\testMVC\test.db
Applying migration '20160304133144_testMigration'.
System.NotSupportedException: SQLite cannot support this migration operation.
в Microsoft.Data.Entity.Migrations.SqliteMigrationsSqlGenerator.Generate(Drop
ForeignKeyOperation operation, IModel model, RelationalCommandListBuilder builde
r)
в Microsoft.Data.Entity.Migrations.MigrationsSqlGenerator.<>c.<.cctor>b__50_1
0(MigrationsSqlGenerator g, MigrationOperation o, IModel m, RelationalCommandLis
tBuilder b)
в Microsoft.Data.Entity.Migrations.MigrationsSqlGenerator.Generate(MigrationO
peration operation, IModel model, RelationalCommandListBuilder builder)
в Microsoft.Data.Entity.Migrations.MigrationsSqlGenerator.Generate(IReadOnlyL
ist`1 operations, IModel model)
в Microsoft.Data.Entity.Migrations.SqliteMigrationsSqlGenerator.Generate(IRea
dOnlyList`1 operations, IModel model)
в Microsoft.Data.Entity.Migrations.Internal.Migrator.GenerateUpSql(Migration
migration)
в Microsoft.Data.Entity.Migrations.Internal.Migrator.<>c__DisplayClass12_4.<G
etMigrationCommands>b__10()
в Microsoft.Data.Entity.Migrations.Internal.Migrator.Migrate(String targetMig
ration)
в Microsoft.Data.Entity.Design.MigrationsOperations.UpdateDatabase(String tar
getMigration, String contextType)
в Microsoft.Data.Entity.Commands.Program.Executor.<>c__DisplayClass7_0.<Updat
eDatabase>b__0()
в Microsoft.Data.Entity.Commands.Program.Executor.Execute(Action action)
SQLite cannot support this migration operation.
而這個問題：我該怎麼辦才能解決這個問題？