Order by date from two tables using Union alternative

Question

I have this two tables

comments

| ID | COMMENT | FULLNAME       | PHOTO_ID |           CREATED_AT            |
|----|---------|----------------|----------|---------------------------------|
| 76 | comment1| John Smith     |       14 | February, 25 2014 10:38:02+0000 |
| 77 | comment2| James Anderson |       14 | February, 25 2014 10:38:14+0000 | 
| 78 | comment3| Will Smith     |       15 |    March, 11 2014 14:24:08+0000 |

views

| ID | USER | PID |           CREATED_AT            |
|----|------------|---------------------------------|
| 63 | user1| 15  | February, 25 2014 11:12:03+0000 |
| 64 | user1| 14  | February, 25 2014 11:14:10+0000 | 
| 66 | user2| 15  | February, 25 2014 11:15:16+0000 |
| 68 | user2| 14  | February, 25 2014 10:38:12+0000 |

I would like to get the values from comments.comment, comments.fullname, views.user so I can use them into a foreach and the results will order by date like so:

John Smith added a comment February, 25 2014 10:38:12 //comment1 user2 viewed the file February, 25 2014 10:38:12 //view James Anderson added a comment February, 25 2014 10:38:12 //comment2

I'm using this query using UNION but I don't think it's the right approach since I can't use the fullname to tell who is writing the comment or the user viewing the file

SELECT comment, fullname, comments.created_at
FROM comments
WHERE comments.photo_id = 14
UNION
SELECT user, '', views.created_at
FROM views
WHERE views.pid = 14
ORDER BY created_at DESC

And the result is

|  COMMENT |       FULLNAME |                      CREATED_AT |
|----------|----------------|---------------------------------|
|    user1 |                | February, 25 2014 11:14:10+0000 |
| comment2 | James Anderson | February, 25 2014 10:38:14+0000 |
|    user2 |                | February, 25 2014 10:38:12+0000 |
| comment1 |     John Smith | February, 25 2014 10:38:02+0000 |

So, is there another way to combine this two tables, order them by date and get the rows individually? Here's the sqlfiddle.

Answer 1

Not 100% sure if this is what you're looking for, but you could give it a try…

SELECT IF(comment = 'view', 'view', 'comment') AS type, comment, fullname, created_at
FROM
(
  SELECT comment, fullname, comments.created_at
  FROM comments
  WHERE comments.photo_id = 14
  UNION
  SELECT 'view', user, views.created_at
  FROM views
  WHERE views.pid = 14
) tbl
ORDER BY created_at DESC

sqlfiddle

Answer 2

This should do the trick:

SELECT
    USER, ACTION, TIME
FROM
    (
    SELECT
         FULLNAME as USER
        ,'COMMENT' as ACTION
        ,CREATED_AT as TIME
    FROM comments
    )
    UNION ALL
    (
    SELECT
         USER as USER
        ,'VIEW' as ACTION
        ,CREATED_AT as TIME
    FROM views
    )
WHERE
    VIEWS_PID = 14
OERDER BY
    TIME DESC