Question

So i have 2 tables which does not have any column in common and i want to store them by their date column

So table1 is like:

table1

• id
• post_id
• post_date

table2

• id
• comment_id
• comment_date

what i want to show is everything from table1,table2 and sort it by date

i tried something like

SELECT * FROM table1 INNER JOIN table2 ORDER BY post_date DESC, comment_date DESC

the problem is that i dont know how to identify which item(post or comment) i am using inside the while(rows = mysql_fetch_assoc()) since i have different column names.

Solution was:

                SELECT * FROM (
                SELECT 1 AS `table`, `col1` AS `userid`, `col2` AS `cat`, `col3` AS `item_id`, `title` AS `title`, etc... , `date` AS `date` FROM `table1`
                UNION
                SELECT 2 AS `table`, `col1` AS `userid`, `col2` AS `cat`, `col3` AS `item_id`, NULL AS `title`, etc... , `date` AS `date` FROM `table2`
            ) AS tb
            ORDER BY `date` DESC

Answer 1

                SELECT * FROM (
            SELECT 1 AS `table`, `col1` AS `userid`, `col2` AS `cat`, `col3` AS `item_id`, `title` AS `title`, etc... , `date` AS `date` FROM `table1`
            UNION
            SELECT 2 AS `table`, `col1` AS `userid`, `col2` AS `cat`, `col3` AS `item_id`, NULL AS `title`, etc... , `date` AS `date` FROM `table2`
        ) AS tb
        ORDER BY `date` DESC