I seem to be unable to use the ActiveRecord::Base.find option :order for more than one column at a time.
For example, I have a ‘Show’ model with date and attending columns.
If I run the following code:
@shows = Show.find(:all, :order => 'date') I get the following results:
[#<Show id: 7, date: '2009-04-18', attending: 2>, #<Show id: 1, date: '2009-04-18', attending: 78>, #<Show id: 2, date: '2009-04-19', attending: 91>, #<Show id: 3, date: '2009-04-20', attending: 16>, #<Show id: 4, date: '2009-04-21', attending: 136>] If I run the following code:
@shows = Show.find(:all, :order => 'attending DESC') [#<Show id: 4, date: '2009-04-21', attending: 136>, #<Show id: 2, date: '2009-04-19', attending: 91>, #<Show id: 1, date: '2009-04-18', attending: 78>, #<Show id: 3, date: '2009-04-20', attending: 16>, #<Show id: 7, date: '2009-04-18', attending: 2>] But, if I run:
@shows = Show.find(:all, :order => 'date, attending DESC') OR
@shows = Show.find(:all, :order => 'date, attending ASC') OR
@shows = Show.find(:all, :order => 'date ASC, attending DESC') I get the same results as only sorting by date:
[#<Show id: 7, date: '2009-04-18', attending: 2>, #<Show id: 1, date: '2009-04-18', attending: 78>, #<Show id: 2, date: '2009-04-19', attending: 91>, #<Show id: 3, date: '2009-04-20', attending: 16>, #<Show id: 4, date: '2009-04-21', attending: 136>] Where as, I want to get these results:
[#<Show id: 1, date: '2009-04-18', attending: 78>, #<Show id: 7, date: '2009-04-18', attending: 2>, #<Show id: 2, date: '2009-04-19', attending: 91>, #<Show id: 3, date: '2009-04-20', attending: 16>, #<Show id: 4, date: '2009-04-21', attending: 136>] This is the query being generated from the logs:
[4;35;1mUser Load (0.6ms)[0m [0mSELECT * FROM 'users' WHERE ('users'.'id' = 1) LIMIT 1[0m [4;36;1mShow Load (3.0ms)[0m [0;1mSELECT * FROM 'shows' ORDER BY date ASC, attending DESC[0m [4;35;1mUser Load (0.6ms)[0m [0mSELECT * FROM 'users' WHERE ('users'.'id' = 1) [0m Finally, here is my model:
create_table 'shows', :force => true do |t| t.string 'headliner' t.string 'openers' t.string 'venue' t.date 'date' t.text 'description' t.datetime 'created_at' t.datetime 'updated_at' t.decimal 'price' t.time 'showtime' t.integer 'attending', :default => 0 t.string 'time' end What am I missing? What am I doing wrong?
UPDATE: Thanks for all your help, but it seems that all of you were stumped as much as I was. What solved the problem was actually switching databases. I switched from the default sqlite3 to mysql.
I notice that in your first example, the simple :order => ‘date’, record 7 is sorted before record 1. This order is also how you see the results in the multi-column sort, regardless of whether you sort by attending.
This would seem to make sense to me if the dates weren’t exactly the same, and the date for 7 is before the date for 1. Instead of finding that the dates are exactly equal then proceeding to sort by attending, the query finds that the dates are not equal and simply sorts by that like all the other records.
I see from browsing around that SQLite doesn’t have a native understanding of DATE or DATETIME data types and instead gives users the choice of floating point numbers or text that they must parse themselves. Is it possible that the literal representation of the dates in the database are not exactly equal? Most people seem to need to use date functions so that dates behave like you would expect. Perhaps there’s a way to wrap your order by column with a date function that will give you something concrete to compare, like date(date) ASC, attending DESC. I’m not sure that syntax works, but it’s an area to look at for solving your problem. Hope that helps.