Find by multiple conditions in rails

问题

I want to search a table with multiple conditions in Rails. I am using Active record and rails version 3.1.0.

I have Movies object, and want to achieve the equivalent of the following in rails:

Select * from Movies where rating = 'R' OR rating = 'PG'

I tried the following but it does not work

@filtered = Movies.find(:all, :conditions => { :rating => 'R', :rating => 'PG' })

Can you please provide help to write an equivalent of SQL query mentioned above.

回答1:

One way would be to build an "IN" condition with:

 @filtered = Movie.where(:rating => ['R', 'PG']).all

EDIT: I changed your class to "Movie" from "Movies". I assume that's what you will want.

回答2:

In Rail 4, find with multiple conditions for example consider find Profile with first_name and last_name

Profile.find_by first_name: 'stack', last_name: 'flow' 

Finds the first record matching the specified conditions. There is no implied ordering so if order matters, you should specify it yourself. If no record is found, returns nil

Profile.find_by! first_name: 'stack', last_name: 'flow'

Like find_by, except that if no record is found, raises an ActiveRecord::RecordNotFound error.

For more information read Rails Finder Method

1: http://api.rubyonrails.org/classes/ActiveRecord/FinderMethods.html#method-i-find_byIn Rail 4, find with multiple conditions for example consider find Profile with first_name and last_name

Profile.find_by first_name: 'stack', last_name: 'flow' 

Finds the first record matching the specified conditions. There is no implied ordering so if order matters, you should specify it yourself. If no record is found, returns nil

Profile.find_by! first_name: 'stack', last_name: 'flow'

Like find_by, except that if no record is found, raises an ActiveRecord::RecordNotFound error.

For more information read Rails Finder Method

回答3:

i guess that would be

Movie.where("rating = ? OR rating = ?", 'R', 'PG')

have a look at the guides for more info: http://guides.rubyonrails.org/active_record_querying.html#conditions

i would recommend using an IN statement instead.

回答4:

You can do it using:

Movie.where(:rating => ['R','PG'])

来源：https://stackoverflow.com/questions/11829850/find-by-multiple-conditions-in-rails