select distinct Coalesce(F,'?')||'|'||Coalesce(M,'?')||'|'||Coalesce(P,'?')||'|'||Coalesce(LAN,'?') as KEY1, ....
- I don't understand what the "||" does here in above code, to join the strings returned from the coalesce?
Thank you!
sql coalesce function and join strings
