How can I query activities for a given week except for the day with name equal to the string "summary"?
Activity.where(:week => wk, :day => "Summary").each do |daily_activity|
end
How do you express the negation? And show the activities for each day in the week, but not when the day is "Summary" (as it's not an actual day).
You can't do it directly with a hash, but you can do it with something like the following:
Activity.where(:week => wk).where('day != ?', 'Summary')
If you want expanded options for finders, check out the squeel gem.
Related
I have a model with attributes start_date and end_date. I have search form where user will put the date and I should get a data from the model if date is in between start_date and end_date.
how should I create a query with thinking sphinx.
You will need to do something like the following:
Add both start_date and end_date as attributes (not fields) to your model's Sphinx index.
Translate form params into a date or time value
Use range filters to limit search queries.
I've opted for very large windows of time, but essentially this ensures the given date is equal to or larger than the start date and less than or equal to the end date.
beginning, ending = Time.utc(1970), Time.utc(2030)
Model.search :with => {
:start_date => beginning..date_from_params,
:end_date => date_from_params..ending
}
I have a model called Story that I'm trying to order by the created_at date. Since I've hosted my app on Heroku, which uses Postgresql, I have the following in my controller:
#stories = Story.find( :all, :order => "DATE(created_at) DESC" , :limit => 11)
I would expect this to give the first 11 of my stories, ordered by the creation date, with the newest story first.
Unfortunately, this doesn't work. Most of the stories return ordered correctly, but the first two are flipped. That is, the latest story appears second in the list.
Why would this be? I have a sneaky suspicion that my results aren't ordered at all or are being ordered on the wrong column (maybe id?) and that until now it just happened to be ordered like I expected when displayed on my index page. How can I get it to order as I expect it to?
In case anyone cares, the index view is simply displaying the stories, in order. That is (HAML):
- #stories.each do |story|
= render :partial => "event", :locals => { :event => story }
EDIT
I am suspicious that the created_at is a datetime column and the DATE(...) function disregards the time portion. So it returns the elements created on the same date in a random order. Since the first two stories were created on the same day, but several hours apart, which would explain why they seem to be 'reversed'. If this is the case, what would be the correct syntax to order by both date and time?
I believe you want:
#stories = Story.find(:all, :order => "created_at DESC" , :limit => 11)
Update for Rails 3+:
#stories = Story.order(created_at: :desc).limit(11)
If you are using Rails 3, I would also encourage you to use the cool new query syntax which would be:
#stories = Story.order('created_at DESC').limit(11)
See Active Record Query Interface for more information.
I have a model (Expense) that contains fields like 'cost'.
I'd like to iterate through all my expenses to find the sum of the cost for all entries belonging to a particular month.
Is there a way to do it in rails directly?
Expense.find(:all, :conditions => .....)
To get the SUM of costs for the month of a given date:
# date = any day of the month of intrest
Expense.sum(:cost, :conditions => {:created_at =>
(date.beginning_of_month..date.end_of_month)})
To get the sum of costs of all the months:
Expense.sum(:cost,
:group => "EXTRACT(YEAR_MONTH FROM created_at)").each do |y_m, cost_sum|
p "#{y_m}-#{cost_sum}"
end
In the above call, use the conditions option to restrict the result-set to a date range.
sum/group_by:
Expense.find(:all,
:select => "SUM(cost) as cost_sum, MONTH(date) as month, YEAR(date) as year",
:group => "MONTH(date), YEAR(date)" )
Have a look at this beautiful gem: https://github.com/radar/by_star
I'm trying to count the number of rows in a certain table by datetime.
More specifically, by a certain month, but can't find the right way to
write the conditions for it.
xxx.count(:all, :conditions=> :xxx => yyy)
I have a datetime yyy to compare with xxx, but only want to compare the year and month.
The more efficient way is like this:
range = Date.today.beginning_of_month..Date.today.end_of_month
Model.count(:conditions => {:date_field => range})
This will generate a range condition, which, if you have an index on the date_field will be very fast even for millions of rows.
I have a plugin/gem called by_star which you can install using just sudo gem install by_star if you have gemcutter.org as one of your sources.
This plugin allows you to do this:
Post.by_month("January", :year => 2009)
Which will return all records from the Post model from January 2009.
This might work.
:conditions => ["month(date_field) = ? AND year(date_field) = ?", month, year]
I have a database with some fields I'd like to sum. But that's not the big problem, I want to group those fields by the month they were created. ActiveRecord automaticaly created a field named "created_at". So my question; how can I group the result by month, then sum the fields for each month?
Updated with code
#hours = Hour.all(:conditions => "user_id = "+ #user.id.to_s,
:group => "strftime('%m', created_at)",
:order => 'created_at DESC')
This is the code I have now. Managed to group by month, but doesn't manage to sum two of my fields, "mins" and "salary" which I need to sum
You can use active record calculations to do this. Some example code might be
Model.sum(:column_name, :group => 'MONTH("created_at")')
Obviously with the caveat MONTH is mysql specific, so if you were developing on an SQLite database this would not work.
I don't know if there's a SQL query you use to do it (without changing your current table structure). However, you do it with some lines of code.
records = Tasks.find(:conditions => {..})
month_groups = records.group_by{|r| r.created_at.month}
month_groups.each do |month, records|
sum stuff.. blah blah blah..
end
I saw this link on the right side of this question. I assume other databases, besides MySQL have similar functions.
mysql select sum group by date
Fixed it by using :select when getting the query, inputing selects manually
#hours = Hour.all(:conditions => "user_id = "+ #user.id.to_s,
:select => "created_at, SUM(time) time",
:group => "strftime('%m', created_at)",
:order => 'created_at DESC')