I have two tables, each with a column of type datetime,
tbl_parent.parent_datetime, tbl_child.child_datetime. Then I want to
count how many children a parent entry have and retrieve the latest
parent entry OR the parent entry with the latest child entry. Therefore
I need to ORDER BY parent_datetime and child_datetime as one column. So
far, I haven't found a way to do this. Maybe there is some way I can
SELECT and merge the two columns and then ORDER BY that? Cause "ORDER BY
tbl_parent.parent_datetime AND tbl_child.child_datetime" doesn't seem to
work. Any help would be appreciated, thanks.
