我们将我们的代码从以下内容进行了更改：
dbMgConfig.AutomaticMigrationDataLossAllowed = false;
var mg = new DbMigrator(dbMgConfig);
mg.Update(null);
to
dbMgConfig.AutomaticMigrationDataLossAllowed = true;
var mg = new DbMigrator(dbMgConfig);
var scriptor = new MigratorScriptingDecorator(mg);
string script = scriptor.ScriptUpdate(sourceMigration: null, targetMigration: null);
throw new Exception(script);
这样我们就能观察DbMigrator在远程服务器上所做的更改。
在本问题开头概述的情况下（即同事上传创建数据库，然后我在另一台机器上生成的上传文件），会生成以下SQL语句：
ALTER TABLE [GalleryImages] DROP CONSTRAINT [FK_GalleryImages_Galleries_Gallery_Id]
ALTER TABLE [GalleryImages] DROP CONSTRAINT [FK_GalleryImages_Images_Image_Id]
ALTER TABLE [UserLightboxes] DROP CONSTRAINT [FK_UserLightboxes_Users_User_Id]
ALTER TABLE [UserLightboxes] DROP CONSTRAINT [FK_UserLightboxes_Lightboxes_Lightbox_Id]
ALTER TABLE [ImageLightboxes] DROP CONSTRAINT [FK_ImageLightboxes_Images_Image_Id]
ALTER TABLE [ImageLightboxes] DROP CONSTRAINT [FK_ImageLightboxes_Lightboxes_Lightbox_Id]
DROP INDEX [IX_Gallery_Id] ON [GalleryImages]
DROP INDEX [IX_Image_Id] ON [GalleryImages]
DROP INDEX [IX_User_Id] ON [UserLightboxes]
DROP INDEX [IX_Lightbox_Id] ON [UserLightboxes]
DROP INDEX [IX_Image_Id] ON [ImageLightboxes]
DROP INDEX [IX_Lightbox_Id] ON [ImageLightboxes]
CREATE TABLE [ImageGalleries] (
[Image_Id] [int] NOT NULL,
[Gallery_Id] [int] NOT NULL,
CONSTRAINT [PK_ImageGalleries] PRIMARY KEY ([Image_Id], [Gallery_Id])
)
CREATE TABLE [LightboxImages] (
[Lightbox_Id] [int] NOT NULL,
[Image_Id] [int] NOT NULL,
CONSTRAINT [PK_LightboxImages] PRIMARY KEY ([Lightbox_Id], [Image_Id])
)
CREATE TABLE [LightboxUsers] (
[Lightbox_Id] [int] NOT NULL,
[User_Id] [int] NOT NULL,
CONSTRAINT [PK_LightboxUsers] PRIMARY KEY ([Lightbox_Id], [User_Id])
)
CREATE INDEX [IX_Image_Id] ON [ImageGalleries]([Image_Id])
CREATE INDEX [IX_Gallery_Id] ON [ImageGalleries]([Gallery_Id])
CREATE INDEX [IX_Lightbox_Id] ON [LightboxImages]([Lightbox_Id])
CREATE INDEX [IX_Image_Id] ON [LightboxImages]([Image_Id])
CREATE INDEX [IX_Lightbox_Id] ON [LightboxUsers]([Lightbox_Id])
CREATE INDEX [IX_User_Id] ON [LightboxUsers]([User_Id])
DROP TABLE [GalleryImages]
DROP TABLE [UserLightboxes]
DROP TABLE [ImageLightboxes]
ALTER TABLE [ImageGalleries] ADD CONSTRAINT [FK_ImageGalleries_Images_Image_Id] FOREIGN KEY ([Image_Id]) REFERENCES [Images] ([Id]) ON DELETE CASCADE
ALTER TABLE [ImageGalleries] ADD CONSTRAINT [FK_ImageGalleries_Galleries_Gallery_Id] FOREIGN KEY ([Gallery_Id]) REFERENCES [Galleries] ([Id]) ON DELETE CASCADE
ALTER TABLE [LightboxImages] ADD CONSTRAINT [FK_LightboxImages_Lightboxes_Lightbox_Id] FOREIGN KEY ([Lightbox_Id]) REFERENCES [Lightboxes] ([Id]) ON DELETE CASCADE
ALTER TABLE [LightboxImages] ADD CONSTRAINT [FK_LightboxImages_Images_Image_Id] FOREIGN KEY ([Image_Id]) REFERENCES [Images] ([Id]) ON DELETE CASCADE
ALTER TABLE [LightboxUsers] ADD CONSTRAINT [FK_LightboxUsers_Lightboxes_Lightbox_Id] FOREIGN KEY ([Lightbox_Id]) REFERENCES [Lightboxes] ([Id]) ON DELETE CASCADE
ALTER TABLE [LightboxUsers] ADD CONSTRAINT [FK_LightboxUsers_Users_User_Id] FOREIGN KEY ([User_Id]) REFERENCES [Users] ([Id]) ON DELETE CASCADE
CREATE TABLE [__MigrationHistory] (
[MigrationId] [nvarchar](255) NOT NULL,
[CreatedOn] [datetime] NOT NULL,
[Model] [varbinary](max) NOT NULL,
[ProductVersion] [nvarchar](32) NOT NULL,
CONSTRAINT [PK___MigrationHistory] PRIMARY KEY ([MigrationId])
)
BEGIN TRY
EXEC sp_MS_marksystemobject '__MigrationHistory'
END TRY
BEGIN CATCH
END CATCH
INSERT INTO [__MigrationHistory] ([MigrationId], [CreatedOn], [Model], [ProductVersion]) VALUES ('201203030113082_AutomaticMigration', '2012-03-03T01:13:08.986Z', 0x[removedToShortenPost], '4.3.1')
可以看出，
DbMigrator抛出异常的原因是它正试图重命名用于连接多对多关系的3个表，通过反转它们所连接的表的名称，例如将
GalleryImages改为
ImageGalleries或
UserLightboxes改为
LightboxUsers。
解决方法
这似乎是EF 4.3中的一个错误，其中“association”表的命名似乎是不确定的。鉴于这些类型的表格的名称排序似乎未定义/不确定，我们从不同的角度来解决这个问题，使用流畅的API来强制EF在不同机器上使用一致的命名：
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder
.Entity<Gallery>()
.HasMany(p => p.Images)
.WithMany(p => p.Galleries)
.Map(c =>
{
c.MapLeftKey("Gallery_Id");
c.MapRightKey("Image_Id");
c.ToTable("GalleryImages");
});
modelBuilder
.Entity<User>()
.HasMany(p => p.Lightboxes)
.WithMany(p => p.Users)
.Map(c =>
{
c.MapLeftKey("User_Id");
c.MapRightKey("Lightbox_Id");
c.ToTable("UserLightboxes");
});
modelBuilder
.Entity<Image>()
.HasMany(p => p.Lightboxes)
.WithMany(p => p.Images)
.Map(c =>
{
c.MapLeftKey("Image_Id");
c.MapRightKey("Lightbox_Id");
c.ToTable("ImageLightboxes");
});
}
有了这个设置，错误现在消失了。
Update-Database -Script -SourceMigration $InitialDatabase -Force并比较两个输出结果？ - bricelam