环境：vs2015 ＋ EF6 ＋ODP 数据库Oracle 11G

add-migratioin 正常，但在update-database 时报如下错误：

System.Runtime.Serialization.SerializationException: Type is not resolved for member 'Oracle.ManagedDataAccess.Client.OracleException,Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342'

解决办法如下：

Installing Oracle.ManagedDataAccess.dll to GAC resolved my issue. If you installed Oracle Client or Oracle Database on your machine that might be the cause.

:\Windows\system32>cd E:\smn\packages\Oracle.ManagedDataAccess.\lib\net40

C:\Windows\system32>e:

E:\smn\packages\Oracle.ManagedDataAccess.\lib\net40>"C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A\bin\NETFX 4.5.1 Tools\gacutil.exe" /i Oracle.ManagedDataAccess.dll
Microsoft (R) .NET Global Assembly Cache Utility.  Version 4.0.30319.33440
Copyright (c) Microsoft Corporation.  All rights reserved.

Assembly successfully added to the cache

注意：cmd要用管理员权限运行。