How to specify dynamic field names in a Linq where clause?
- by Dr. Zim
If you create a Filter object that contains criteria for Linq that normally goes in a where clause like this:
var myFilterObject = FilterFactory.GetBlank();
myFilterObject.AddCondition("Salary", "lessThan", "40000");
var myResult = myRepository.GetEmployees(myFilterObject);
How would you match the Linq field to the Field Name without using a big case statement?
return from e in db.Employee
where e.Salary < 40000
select new IList<EmployeeViewModel> { Name= e.name, Salary= e.Salary };
I assume you need to send an object to the Repository that specifies filtering so that you only pull what records you need. I assume Linq doesn't pre-compile (unless you create a customized delegate and function), so you should be able to dynamically specify which fields you want to filter.
It would be nice if you could do something like e["Salary"] like some type of Expando Object.
