Linq To Entities 解密特定列

Question

我的应用程序是 MVC 5，使用 EF 6.3。我正在尝试使用以下内容解密两列：

var grid = db.mytable.Where(c => c.Item== "Order").Select(c => new
            {
                FirstName = Encryption.Decrypt(c.FirstName),
                LastName = Encryption.Decrypt(c.LastName),
                Id = c.Id
             }).ToList();

我收到这个错误：

LINQ to Entities does not recognize the method 'System.String Decrypt(System.String)' method, and this method cannot be translated into a store expression.

Answer 1

问题是 EF 正在尝试将您的 Select 中的代码转换为 SQL，但没有将 Encryption.Decrypt 方法转换为 SQL。相反，您需要执行查询，然后对结果集进行解密。

这可以通过在 Select 之前添加 ToList() 来强制执行

var grid = db.mytable.Where(c => c.Item== "Order").ToList().Select(c => new
            {
                FirstName = Encryption.Decrypt(c.FirstName),
                LastName = Encryption.Decrypt(c.LastName),
                Id = c.Id
             }).ToList();

Answer 2

您应该 .ToList() 使您的查询变为 Immediate Query Execution。在那之后，你可以做任何你想做的事情。

var filteredTable = db.mytable.Where(c => c.Item== "Order").ToList();
var grid = filteredTable .Select(c => new
            {
                FirstName = Encryption.Decrypt(c.FirstName),
                LastName = Encryption.Decrypt(c.LastName),
                Id = c.Id
             }).ToList();

Linq To Entities 解密特定列

Linq To Entities Decryption of specific columns

c#

asp.net-mvc

encryption

linq-to-entities