MVC網站使用多個資料庫(Code First)

下命令時需指定使用哪個DataContext

-Verbose 可以觀察migration流程

1. enable-migrations -ContextTypeName MultiDataContextMigrations.Models.DataContext -MigrationsDirectory:DataContextMigrations
2. 
   
3. Add-Migration -configuration MultiDataContextMigrations.DataContextMigrations.Configuration Initial
4. 
   
5. Update-Database -configuration MultiDataContextMigrations.DataContextMigrations.Configuration -Verbose

MVC用EF存取MYSQL資料庫時產生的不明問題解決方式

以現有資料庫產生EF架構，有時候會發現，在寫入資料時會有不明原因的報錯

錯誤訊息 Error “You have an error in your sql syntax entity framework” with Entity Framework


目前查到的解決方法如下:

1. 右鍵點擊產生的edmx檔，用有編碼的xml打開
2. 搜尋DefiningQuery 這個Tag，然後把它砍了
3. 之後就一切正常了


參考網頁
What happened is that at the moment of executing db.SaveChanges() (after an update), the .edmx tried to update the rows in the 'C' table, but as this table only had two foreign keys to A and B, the update operation wasn't supported. This is the solution that I found in other post in StackOverflow, and it worked for me:

1. Right click on the edmx file, select Open with, XML editor
2. Remove the DefiningQuery entirely
3. Rename the store:Schema="dbo" to Schema="dbo (remove the "store:")
4. Remove the store:Name=... property (entirely)