Create a 'timeline' with multiple tables (SQL)

Question

I'm trying to create a timeline of action that the user did (when I use his email address).

Example:

• Subscribe to the newsletter (16/12 09h00)
• Open the newsletter (16/12 10h22)
• Click on a link (16/12 10h34)
• Click on a link (16/12 10h37)

I've 3 tables I want to use in my timeline:

• landing (landing_email, landing_date)
• tracker (tracker_email, tracker_date)
• links (links_email, links_date)

So, the only common point is the email address (and the column has a different name in each table).

I've tried a lot of solutions but they didn't work with my case.

Answer 1

You can use a UNION like:

SELECT Email, DateTime FROM
  (SELECT landing_email as Email, landing_date as DateTime FROM landing 
   UNION 
   SELECT tracker_email as Email, tracker_date as DateTime FROM tracker
   UNION
   SELECT links_email as Email, links_date as DateTime FROM links)
WHERE EMAIL='user@domain.com'
ORDER BY DateTime;