How to use Scalar Value functions in EntityFramework Query - entity-framework-6

Question

I have a scalar valued function as below:
CREATE FUNCTION [dbo].[GetCustomersTime]
(
#TimeSpanType char(1),
#TimeSpan int,
#CurrentUtc datetime
)
RETURNS datetime
AS
BEGIN
DECLARE #CustomersTime DATETIME;
SELECT #CustomersTime = CASE UPPER(#TimeSpanType)
WHEN 'S' THEN DATEADD(Second, #TimeSpan, #CurrentUtc)
WHEN 'I' THEN DATEADD(Minute, #TimeSpan, #CurrentUtc)
WHEN 'H' THEN DATEADD(Hour, #TimeSpan, #CurrentUtc)
WHEN 'D' THEN DATEADD(Day, #TimeSpan, #CurrentUtc)
WHEN 'W' THEN DATEADD(Week, #TimeSpan, #CurrentUtc)
WHEN 'M' THEN DATEADD(Month, #TimeSpan, #CurrentUtc)
WHEN 'Q' THEN DATEADD(Quarter, #TimeSpan, #CurrentUtc)
WHEN 'Y' THEN DATEADD(Year, #TimeSpan, #CurrentUtc)
ELSE DATEADD(SECOND, #TimeSpan, #CurrentUtc)
END;
RETURN #CustomersTime
END
I would like to use this function in the Entity Framework Query. The query I would like to achieve is below:
SELECT c.CustomerId, c.FirstName, c.LastName, c.OrderDateUtc
FROM dbo.Customer c
--Other INNER JOINs
WHERE dbo.GetCustomersTime(c.[TimeSpanType], c.[TimeSpan], c.OrderDateUtc) > GetUtcDate()
--Additional Conditions
My entity framework query is:
(from c in _context.Customers
//additional joins
where //how to use function
select new
{
c.CustomerId,
c.FirstName,
c.LastName,
c.OrderDateUtc
}).ToList();
Some suggested to use a project and have the GetCustomersTime function in the EF query. But I could not find a real example. Can anyone help with this?

Answer 1

Try the following:
Declare a function in the (SSDL) of your .edmx file. The name of the
function must be the same as the name of the function declared in the
database.
Add a corresponding method to a class in your application code and
apply a EdmFunctionAttribute to the method.
Call the method in a LINQ to Entities query.
For more details check this link.

Answer 2

Looks like I should have searched it better. I found the solution suggested here. The github link is CodeFirstFunctions.