MySQL matching 2 out of 5 fields

Question

In MySQL I\'m trying to select any row that matches at least 2 fields of the provided data

Eg. I have been given firstName, lastName, dob, website, email and I want

Answer 1

SELECT
(CASE WHEN Field1 = Value1 THEN 1 ELSE 0 END
+CASE WHEN Field2 = Value2 THEN 1 ELSE 0 END
...
+CASE WHEN FieldN = ValueN THEN 1 ELSE 0 END
)
AS Conditions
From YourTable
WHERE Conditions >= (Min_Number_Of_Fields)

Answer 2

You could count up the matching expressions. MySQL returns 1 for true and 0 for false.

WHERE (FirstName = ?) + (LastName = ?) + (... = ?) > 2

You can also order using this as well. You will want to sort descending to ensure that the higher matches appear first.

ORDER BY ((FirstName = ?) + (LastName = ?) + (... = ?)) DESC

Answer 3

As a'r's answer recommended, you can add together values. If you want to use this for ranking, you might not include it in the where clause as he did.

SELECT *, ((firstName = @inputFirst) + (lastName = @inputLast) + (dob = @inputDob) + (website = @inputWebsite) + (email = @inputEmail)) as Matches
FROM mytable
HAVING Matches > 1
ORDER BY Matches DESC

I don't have access to a mysql db to test this syntax at the moment, but I believe it should work properly.