Fetch same columns from two tables

[gionna]

I am very going through a very basic query and need help from Experts. Please help me. I am using "MySQL" here:

SELECT c.first_name,
       c.last_name,
       c.email
       l.first_name,
       l.last_name,
       l.email
from users u
INNER JOIN contacts c ON u.id = c.user_id
LEFT JOIN leads l ON c.id = l.contact_id
where u.user_id=850
-- and l.contact_id is not NULL

Can I get the first_name, last_name in one column if contact id is not null in lead table.both table has same values

I know I have not provided the good details but can provide if asked... any help will be appreciated.

[rosemadder]

A bit of guessing:

SELECT c.first_name,
   c.last_name,
   c.email
   NULLIF(L.FIRST_NAME, C.FIRST_NAME) 
   ... 
   ... 
from users u
INNER JOIN contacts c ON u.id = c.user_id
LEFT JOIN leads l ON c.id = l.contact_id
where u.user_id=850