Question

Is there something like ISNULL() OR COALESCE() but not that checks for null value but for an empty value.

for example:

  SELECT cu.last_name, cu.first_name, cu.email, hu.email FROM 
 (SELECT DISTINCT c.first_name, c.last_name, c.email, c.household_id, h.head_of_household_id
  FROM rd_customers c
  JOIN rd_households h ON c.household_id = h.household_id
  JOIN ad_registrations r ON r.customer_id = c.customer_id
  JOIN ad_meeting_times a ON  r.session_id = a.session_id and a.meeting_time_id = 203731) cu
  LEFT JOIN rd_customers hu ON hu.customer_id = cu.head_of_household_id

instead of returning four columns I’d like to get three and the third one suppose to have values either of cu.email or hu.email if the first one is EMPTY!
ISNULL and COALESCE don’t work here i dunno why

Answer 1

You can always use case:

select  case when cu.email is null or cu.email = '' then hu.email 
             else cu.email end as ColumnName
from    YourTable