Question

Maybe I’m looking at this problem all wrong, but here goes.

We have a database that is the backend for some CRM software we use in the office. The boss wants a simple query to extract birthdays from clients and their spouses.

The table structure is as follows:

Client Details Table:
Client Name, Client Birthday, Spouse Name, Spouse Birthday, <etc>

I have a simple query with a case select that will determine if the client’s birthday or the spouse’s birthday is any time in the next month.

Query is compacted as follows:

SELECT a.*
FROM
  (SELECT
     (CASE    WHEN <birthday calculation>
              ELSE NULL 
      END) as WhoHasBDay,
      ClientName,
      SpouseName
   FROM
     ClientDetailsTable) as a
WHERE
   a.WhoHasBDay IS NOT NULL

This will return any entries where the client or the spouse has a birthday in the next X days.

However, if a client AND their spouse has a birthday in the next X days, I would like the query to return the result once for each.

IE, here is the following data

CLIENT X: Birthday in 5 days
CLIENT Y: Spouse's Birthday in 8 days
CLIENT Z: Birthday in 3 days, Spouse's Birthday in 9 days.

The result set I want is

CLIENT X BDAY T+5
CLIENT Y SPOUSE BDAY T+8
CLIENT Z BDAY T+3
CLIENT Z SPOUSE BDAY T+9

Perhaps I’m approaching this problem the wrong way, in which case suggestion on a better method of attacking it would be appreciated. Otherwise if there’s a solution to this, please let me know.

Answer 1

I’d tackle this as a UNION of two separate queries: one for clients and one for their spouses.

SELECT ClientName, NULL AS SpouseName, Birthday
    FROM ClientDetailsTable
    WHERE <birthday calculation is true>
UNION ALL
SELECT ClientName, SpouseName, SpouseBirthday
    FROM ClientDetailsTable
    WHERE <spouse birthday calculation is true>