SQL: Match a variable value with multiple columns and select matching column name

I want to get the record with matching phone number. There are total 3 columns that saves phone numbers. Work, home and cellphone. I am writing a query to check if the phone number matches with any of the 3 columns.

declare @phNo nvarchar(15) = 'xxxxxxxxxx'

select HomePhone, cellphone, workphone, * 
from Contact_Table 
where @phNo in (HomePhone, cellphone, workphone)

This query is working fine, but I also want the name of the column which matches with the phone number. How can I get the matching column’s name?

For example if the phone number matches with ‘homehpone’ then the result set should return ‘homephone’

Answer

This can be done with CASE:

DECLARE @phNo NVARCHAR(15) = 'xxxxxxxxxx';

SELECT homephone,cellphone,workphone, *,
       CASE WHEN @phNo = homephone THEN 'homephone'
            WHEN @phNo = cellphone then 'cellphone'
            WHEN @phNo = workphone THEN 'workphone'
            END AS PhoneMatch
FROM Contact_Table
WHERE @phNo IN (HomePhone,cellphone,workphone);