I have 2 CTE’s with the 2 columns each. There are NO null values in either CTE.

When I use FULL OUTER JOIN with coalesce im still getting NULL values which is baffling to me.

...
SELECT
  coalesce(c.email, o.email) email,
  o.campaign_opens,
  c.campaign_clicks
FROM campaign_opens o
FULL OUTER JOIN campaign_clicks c ON c.email = o.email

Even when I do this:

  coalesce(c.email, o.email, 'x') email,

There are STILL null values returned. So something about this is definitely not what I’m used to with SQL

What dumb thing am I missing?