C#

SELECT TOP 1
    Country
FROM
    CountryCodes
WHERE
    @PhoneNumber Like Code + '%'
ORDER BY
    Len(Code) DESC
;

WITH cteCodes As
(
    SELECT
        CountryCodes.Country,
        PhoneNumbers.PhoneNumber,
        ROW_NUMBER() OVER (PARTITION BY PhoneNumbers.PhoneNumber ORDER BY Len(CountryCodes.Code) DESC) As RN
    FROM
        CountryCodes
        INNER JOIN PhoneNumbers
        ON PhoneNumbers.PhoneNumber Like CountryCodes.Code + '%'
)
SELECT 
    Country,
    PhoneNumber
FROM 
    cteCodes
WHERE
    RN = 1
;

Pete O'Hanlon wrote:

For a lot of people, upgrading to the latest version of C# will be a prohibited move due to workspace constraints.

MyStringResource = "A problem occured in {0}."

string location = "an undefined place";
string message = string.Format(Resources.MyStringResource, location);

Sascha Lefèvre wrote:

interpolation built into C# 6,

public static string
Format
(
  this string              Format
,
  System.Collections.IList Parameter
)

PIEBALDconsult wrote:

The ability to compile against older versions

PIEBALDconsult wrote:

I use the oldest compiler that does what I need.