SQL multiple tables with

Question

I have a SQL database with 2 tables:

Client

ClientID
ClientName
ClientBirthdate

Address

ClientID
Addressline1
Addressline2
Telephone1
Telephone2

It is possible for a client to have multiple addresses, so ClientID is not a unique value in the Address-table. My problem is that I want to send a textmessage to every unique phonenumber. Telephone1 and Telephone2 can both be empty, so basically I have no idea how many unique phonenumbers a client has. When I join them now, it looks something like this:

ClientID  | ClientName | Telephone1 | Telephone2
------------------------------------------------
Client001 | James      | 12345      | 22312
Client001 | James      | 12345      | 
Client002 | Alfred     |            | 11111
Client002 | Alfred     | 11111      | 
Client002 | Alfred     | 22222      | 

While what I want is something like this:

ClientID  | ClientName | Number1    | Number2
----------------------------------------------
Client001 | James      | 12345      | 22312
Client001 | Alfred     | 11111      | 22222

Currently I have no idea how to achieve this. Can anyone shine their light on the issue?

Thanks on beforehand,

James.

EDIT: The database already exists, and is already filled. I can't change the structure of the database, I can only do SELECT-queries.

Answer 1

Here is my suggested solution (if I understood the problem correctly):

SELECT DISTINCT CLIENTID, 
                CLIENTNAME, 
                TELEPHONE 
FROM   (SELECT T1.CLIENTID, 
               T1.CLIENTNAME, 
               T2.TELEPHONE1 AS Telephone 
        FROM   CLIENT T1 
               INNER JOIN (SELECT CLIENTID, 
                                  TELEPHONE1 
                           FROM   ADDRESS 
                           WHERE  TELEPHONE1 IS NOT NULL)T2 
                       ON T1.CLIENTID = T2.CLIENTID 
        UNION 
        SELECT T1.CLIENTID, 
               T1.CLIENTNAME, 
               T2.TELEPHONE2 AS Telephone 
        FROM   CLIENT T1 
               INNER JOIN (SELECT CLIENTID, 
                                  TELEPHONE2 
                           FROM   ADDRESS 
                           WHERE  TELEPHONE2 IS NOT NULL)T2 
                       ON T1.CLIENTID = T2.CLIENTID)T 

You can find a full example on SQL Fiddle.
Please let me know if you have any more question on this.

Answer 2

How about

select distinct ClientID, ClientName, Number1  
  from ...  
union
select distinct ClientID, ClientName, Number2
  from ...  
  where Number2 is not null