Question

ill start of by saying “Yes, i know my table does not conform with 1NF.”
i am working with something old, and can not change it.
so please, no comments about that.

now, to the problem:

select title,address,zip,city, concat(telefon1,',',telefon2,',',telefon3) as phone

the problem with this is, that it works fine until one of the columns in concat is null or empty.
if it is, then i get a Null result for the phone column.
if all three have values, everything works as expected.

how can i overcome this problem ?

Answer 1

Try this:

SELECT title,address,zip,city,CONCAT(
    COALESCE(telefon1,''), ',',
    COALESCE(telefon2,''), ',',
    COALESCE(telefon3,'')) as phone