The problem arises when you have your application compiled for AnyCPU Platform, you are running on a 64bit system and the installed ADO.NET provider (Microsoft ACE.OLEDB.12.0) is the 32bit version. When using the AnyCpu target Platform your code will be executed as 64bit code on 64bit systems and as 32bit code on 32bit systems. An application executed as 64bit cannot use 32bit drivers (and viceversa). The Microsoft.ACE.OLEDB.12.0 has two different version for 64 and 32bit that cannot be installe...
Enity Framework "column in table is of a type that is invalid for use as a key column in an index"
After adding Index attribute with IsUnique set to true for string value in my code first model [Index(IsUnique = true)] public string Email { get; set; } , I've tried to update my database, but got following error: "column in table is of a type that is invalid for use as a key column in an index". I've got this error because unique constraint can't be over 8000 bytes per row and will only use the first 900 bytes even then so the safest maximum size for my field would be 450 characters. To add th...