Linq 到实体，使用 sql not in 运算符

Question

你好 如何通过 linq 编写以下 sql 查询

Select * From Employee where EmployeeId not in (Select EmployeeId in orders)

Answer 1

您可以尝试这个：

var query = from e in context.Employees
            let ids = context.Orders.Select(o => o.Employee.Id)
            where !ids.Contains(e.Id)
            select e;

或这个：

var query = from e in context.Employees
            where !context.Orders.Any(o => o.Empolyee.Id == e.Id)
            select e;