MySQL Connector - LINQ to Entities 无法识别该方法

Question

在我的[项目中，我使用的是 MySQL 连接器和 Entity Framework 。我对以下代码有疑问:

   int now = DateTime.Now.DayOfYear;

   var items = (from e in db.Table1
                let date = e.Created.AddDays(90)
                where date.DayOfYear > now
                select e).ToList(); 

但我收到错误信息:

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

如何解决？

Answer 1

您不能在 linq 查询中使用这些类型的函数，您应该从现在减去 90 天，然后在查询中进行比较

int now = DateTime.Now.DayOfYear.AddDays(-90);
var items = (from e in db.Table1
                where e.Created > now
                select e).ToList();