How to call DB function from EF LINQ query?

Question

In my database I have define some function, let\'s say it\'s called fnTest. Is it possible to call that function from my LINQ/EF query? Something like this:

Answer 1

First off, fnTest will have to be created as a user-defined function in the database first:

CREATE FUNCTION [fnTest] (@fi int, @f2 int, @param3 int, @param4 int)
RETURNS int
AS ...

Then in your .edmx file, declare the function like this:

Now you can bind this function to a method in your model like this:

[EdmFunction("MyNamespace", "fnTest")]
public static int fnTest(int f1, int f2, int param3, int param4)
{
    throw new NotSupportedException("Direct calls are not supported.");
}

You can now use this method in standard LINQ queries.

Further Reading

• How to: Call Custom Database Functions