How do you do an OR query in Rails 3 ActiveRecord. All the examples I find just have AND queries.
Edit: OR method is available since Rails 5. See ActiveRecord::QueryMethods
If you want to use an OR operator on one column's value, you can pass an array to .where and ActiveRecord will use IN(value,other_value):
Model.where(:column => ["value", "other_value"]
outputs:
SELECT `table_name`.* FROM `table_name` WHERE `table_name`.`column` IN ('value', 'other_value')
This should achieve the equivalent of an OR on a single column
in Rails 3, it should be
Model.where("column = ? or other_column = ?", value, other_value)
This also includes raw sql but I dont think there is a way in ActiveRecord to do OR operation. Your question is not a noob question.
Rails 5 added or, so this is easier now in an app with Rails version greater than 5:
Model.where(column: value).or(Model.where(other_column: other_value)
this handles nil values as well
Use ARel
t = Post.arel_table
results = Post.where(
t[:author].eq("Someone").
or(t[:title].matches("%something%"))
)
The resulting SQL:
ree-1.8.7-2010.02 > puts Post.where(t[:author].eq("Someone").or(t[:title].matches("%something%"))).to_sql
SELECT "posts".* FROM "posts" WHERE (("posts"."author" = 'Someone' OR "posts"."title" LIKE '%something%'))
An updated version of Rails/ActiveRecord may support this syntax natively. It would look similar to:
Foo.where(foo: 'bar').or.where(bar: 'bar')
As noted in this pull request https://github.com/rails/rails/pull/9052
For now, simply sticking with the following works great:
Foo.where('foo= ? OR bar= ?', 'bar', 'bar')
Update: According to https://github.com/rails/rails/pull/16052 the or feature will be available in Rails 5
Update: Feature has been merged to Rails 5 branch
Rails has recently added this into ActiveRecord. It looks to be released in Rails 5. Committed to master already:
https://github.com/rails/rails/commit/9e42cf019f2417473e7dcbfcb885709fa2709f89
Post.where(column: 'something').or(Post.where(other: 'else'))
# => SELECT * FROM posts WHERE (column = 'something') OR (other = 'else)
Rails 5 comes with an or method. (link to documentation)
This method accepts an ActiveRecord::Relation object. eg:
User.where(first_name: 'James').or(User.where(last_name: 'Scott'))
If you want to use arrays as arguments, the following code works in Rails 4:
query = Order.where(uuid: uuids, id: ids)
Order.where(query.where_values.map(&:to_sql).join(" OR "))
#=> Order Load (0.7ms) SELECT "orders".* FROM "orders" WHERE ("orders"."uuid" IN ('5459eed8350e1b472bfee48375034103', '21313213jkads', '43ujrefdk2384us') OR "orders"."id" IN (2, 3, 4))
More information: OR queries with arrays as arguments in Rails 4.
The MetaWhere plugin is completely amazing.
Easily mix OR's and AND's, join conditions on any association, and even specify OUTER JOIN's!
Post.where({sharing_level: Post::Sharing[:everyone]} | ({sharing_level: Post::Sharing[:friends]} & {user: {followers: current_user} }).joins(:user.outer => :followers.outer}
Just add an OR in the conditions
Model.find(:all, :conditions => ["column = ? OR other_column = ?",value, other_value])
With rails + arel, a more clear way:
# Table name: messages
#
# sender_id: integer
# recipient_id: integer
# content: text
class Message < ActiveRecord::Base
scope :by_participant, ->(user_id) do
left = arel_table[:sender_id].eq(user_id)
right = arel_table[:recipient_id].eq(user_id)
where(Arel::Nodes::Or.new(left, right))
end
end
Produces:
$ Message.by_participant(User.first.id).to_sql
=> SELECT `messages`.*
FROM `messages`
WHERE `messages`.`sender_id` = 1
OR `messages`.`recipient_id` = 1
You could do it like:
Person.where("name = ? OR age = ?", 'Pearl', 24)
or more elegant, install rails_or gem and do it like:
Person.where(:name => 'Pearl').or(:age => 24)
I just extracted this plugin from client work that lets you combine scopes with .or., ex. Post.published.or.authored_by(current_user). Squeel (newer implementation of MetaSearch) is also great, but doesn't let you OR scopes, so query logic can get a bit redundant.
I'd like to add this is a solution to search multiple attributes of an ActiveRecord. Since
.where(A: param[:A], B: param[:B])
will search for A and B.
Using the activerecord_any_of gem, you can write
Book.where.any_of(Book.where(:author => 'Poe'), Book.where(:author => 'Hemingway')
Related
I'm hoping there is a easy solution that doesn't involve find_by_sql, if not then I guess that will have to work.
I found this article which references this:
Topic.find(:all, :conditions => { :forum_id => #forums.map(&:id) })
which is the same as
SELECT * FROM topics WHERE forum_id IN (<#forum ids>)
I am wondering if there is a way to do NOT IN with that, like:
SELECT * FROM topics WHERE forum_id NOT IN (<#forum ids>)
Rails 4+:
Article.where.not(title: ['Rails 3', 'Rails 5'])
Rails 3:
Topic.where('id NOT IN (?)', Array.wrap(actions))
Where actions is an array with: [1,2,3,4,5]
FYI, In Rails 4, you can use not syntax:
Article.where.not(title: ['Rails 3', 'Rails 5'])
Using Arel:
topics=Topic.arel_table
Topic.where(topics[:forum_id].not_in(#forum_ids))
or, if preferred:
topics=Topic.arel_table
Topic.where(topics[:forum_id].in(#forum_ids).not)
and since rails 4 on:
topics=Topic.arel_table
Topic.where.not(topics[:forum_id].in(#forum_ids))
Please notice that eventually you do not want the forum_ids to be the ids list, but rather a subquery, if so then you should do something like this before getting the topics:
#forum_ids = Forum.where(/*whatever conditions are desirable*/).select(:id)
in this way you get everything in a single query: something like:
select * from topic
where forum_id in (select id
from forum
where /*whatever conditions are desirable*/)
Also notice that eventually you do not want to do this, but rather a join - what might be more efficient.
You can try something like:
Topic.find(:all, :conditions => ['forum_id not in (?)', #forums.map(&:id)])
You might need to do #forums.map(&:id).join(','). I can't remember if Rails will the argument into a CSV list if it is enumerable.
You could also do this:
# in topic.rb
named_scope :not_in_forums, lambda { |forums| { :conditions => ['forum_id not in (?)', forums.select(&:id).join(',')] }
# in your controller
Topic.not_in_forums(#forums)
To expand on #Trung Lê answer, in Rails 4 you can do the following:
Topic.where.not(forum_id:#forums.map(&:id))
And you could take it a step further.
If you need to first filter for only published Topics and then filter out the ids you don't want, you could do this:
Topic.where(published:true).where.not(forum_id:#forums.map(&:id))
Rails 4 makes it so much easier!
The accepted solution fails if #forums is empty. To workaround this I had to do
Topic.find(:all, :conditions => ['forum_id not in (?)', (#forums.empty? ? '' : #forums.map(&:id))])
Or, if using Rails 3+:
Topic.where( 'forum_id not in (?)', (#forums.empty? ? '' : #forums.map(&:id)) ).all
Most of the answers above should suffice you but if you are doing a lot more of such predicate and complex combinations check out Squeel. You will be able to doing something like:
Topic.where{{forum_id.not_in => #forums.map(&:id)}}
Topic.where{forum_id.not_in #forums.map(&:id)}
Topic.where{forum_id << #forums.map(&:id)}
You may want to have a look at the meta_where plugin by Ernie Miller. Your SQL statement:
SELECT * FROM topics WHERE forum_id NOT IN (<#forum ids>)
...could be expressed like this:
Topic.where(:forum_id.nin => #forum_ids)
Ryan Bates of Railscasts created a nice screencast explaining MetaWhere.
Not sure if this is what you're looking for but to my eyes it certainly looks better than an embedded SQL query.
The original post specifically mentions using numeric IDs, but I came here looking for the syntax for doing a NOT IN with an array of strings.
ActiveRecord will handle that nicely for you too:
Thing.where(['state NOT IN (?)', %w{state1 state2}])
Can these forum ids be worked out in a pragmatic way? e.g. can you find these forums somehow - if that is the case you should do something like
Topic.all(:joins => "left join forums on (forums.id = topics.forum_id and some_condition)", :conditions => "forums.id is null")
Which would be more efficient than doing an SQL not in
This way optimizes for readability, but it's not as efficient in terms of database queries:
# Retrieve all topics, then use array subtraction to
# find the ones not in our list
Topic.all - #forums.map(&:id)
You can use sql in your conditions:
Topic.find(:all, :conditions => [ "forum_id NOT IN (?)", #forums.map(&:id)])
Piggybacking off of jonnii:
Topic.find(:all, :conditions => ['forum_id not in (?)', #forums.pluck(:id)])
using pluck rather than mapping over the elements
found via railsconf 2012 10 things you did not know rails could do
When you query a blank array add "<< 0" to the array in the where block so it doesn't return "NULL" and break the query.
Topic.where('id not in (?)',actions << 0)
If actions could be an empty or blank array.
Here is a more complex "not in" query, using a subquery in rails 4 using squeel. Of course very slow compared to the equivalent sql, but hey, it works.
scope :translations_not_in_english, ->(calmapp_version_id, language_iso_code){
join_to_cavs_tls_arr(calmapp_version_id).
joins_to_tl_arr.
where{ tl1.iso_code == 'en' }.
where{ cavtl1.calmapp_version_id == my{calmapp_version_id}}.
where{ dot_key_code << (Translation.
join_to_cavs_tls_arr(calmapp_version_id).
joins_to_tl_arr.
where{ tl1.iso_code == my{language_iso_code} }.
select{ "dot_key_code" }.all)}
}
The first 2 methods in the scope are other scopes which declare the aliases cavtl1 and tl1. << is the not in operator in squeel.
Hope this helps someone.
If someone want to use two or more conditions, you can do that:
your_array = [1,2,3,4]
your_string = "SOMETHING"
YourModel.where('variable1 NOT IN (?) AND variable2=(?)',Array.wrap(your_array),your_string)
I'm hoping there is a easy solution that doesn't involve find_by_sql, if not then I guess that will have to work.
I found this article which references this:
Topic.find(:all, :conditions => { :forum_id => #forums.map(&:id) })
which is the same as
SELECT * FROM topics WHERE forum_id IN (<#forum ids>)
I am wondering if there is a way to do NOT IN with that, like:
SELECT * FROM topics WHERE forum_id NOT IN (<#forum ids>)
Rails 4+:
Article.where.not(title: ['Rails 3', 'Rails 5'])
Rails 3:
Topic.where('id NOT IN (?)', Array.wrap(actions))
Where actions is an array with: [1,2,3,4,5]
FYI, In Rails 4, you can use not syntax:
Article.where.not(title: ['Rails 3', 'Rails 5'])
Using Arel:
topics=Topic.arel_table
Topic.where(topics[:forum_id].not_in(#forum_ids))
or, if preferred:
topics=Topic.arel_table
Topic.where(topics[:forum_id].in(#forum_ids).not)
and since rails 4 on:
topics=Topic.arel_table
Topic.where.not(topics[:forum_id].in(#forum_ids))
Please notice that eventually you do not want the forum_ids to be the ids list, but rather a subquery, if so then you should do something like this before getting the topics:
#forum_ids = Forum.where(/*whatever conditions are desirable*/).select(:id)
in this way you get everything in a single query: something like:
select * from topic
where forum_id in (select id
from forum
where /*whatever conditions are desirable*/)
Also notice that eventually you do not want to do this, but rather a join - what might be more efficient.
You can try something like:
Topic.find(:all, :conditions => ['forum_id not in (?)', #forums.map(&:id)])
You might need to do #forums.map(&:id).join(','). I can't remember if Rails will the argument into a CSV list if it is enumerable.
You could also do this:
# in topic.rb
named_scope :not_in_forums, lambda { |forums| { :conditions => ['forum_id not in (?)', forums.select(&:id).join(',')] }
# in your controller
Topic.not_in_forums(#forums)
To expand on #Trung Lê answer, in Rails 4 you can do the following:
Topic.where.not(forum_id:#forums.map(&:id))
And you could take it a step further.
If you need to first filter for only published Topics and then filter out the ids you don't want, you could do this:
Topic.where(published:true).where.not(forum_id:#forums.map(&:id))
Rails 4 makes it so much easier!
The accepted solution fails if #forums is empty. To workaround this I had to do
Topic.find(:all, :conditions => ['forum_id not in (?)', (#forums.empty? ? '' : #forums.map(&:id))])
Or, if using Rails 3+:
Topic.where( 'forum_id not in (?)', (#forums.empty? ? '' : #forums.map(&:id)) ).all
Most of the answers above should suffice you but if you are doing a lot more of such predicate and complex combinations check out Squeel. You will be able to doing something like:
Topic.where{{forum_id.not_in => #forums.map(&:id)}}
Topic.where{forum_id.not_in #forums.map(&:id)}
Topic.where{forum_id << #forums.map(&:id)}
You may want to have a look at the meta_where plugin by Ernie Miller. Your SQL statement:
SELECT * FROM topics WHERE forum_id NOT IN (<#forum ids>)
...could be expressed like this:
Topic.where(:forum_id.nin => #forum_ids)
Ryan Bates of Railscasts created a nice screencast explaining MetaWhere.
Not sure if this is what you're looking for but to my eyes it certainly looks better than an embedded SQL query.
The original post specifically mentions using numeric IDs, but I came here looking for the syntax for doing a NOT IN with an array of strings.
ActiveRecord will handle that nicely for you too:
Thing.where(['state NOT IN (?)', %w{state1 state2}])
Can these forum ids be worked out in a pragmatic way? e.g. can you find these forums somehow - if that is the case you should do something like
Topic.all(:joins => "left join forums on (forums.id = topics.forum_id and some_condition)", :conditions => "forums.id is null")
Which would be more efficient than doing an SQL not in
This way optimizes for readability, but it's not as efficient in terms of database queries:
# Retrieve all topics, then use array subtraction to
# find the ones not in our list
Topic.all - #forums.map(&:id)
You can use sql in your conditions:
Topic.find(:all, :conditions => [ "forum_id NOT IN (?)", #forums.map(&:id)])
Piggybacking off of jonnii:
Topic.find(:all, :conditions => ['forum_id not in (?)', #forums.pluck(:id)])
using pluck rather than mapping over the elements
found via railsconf 2012 10 things you did not know rails could do
When you query a blank array add "<< 0" to the array in the where block so it doesn't return "NULL" and break the query.
Topic.where('id not in (?)',actions << 0)
If actions could be an empty or blank array.
Here is a more complex "not in" query, using a subquery in rails 4 using squeel. Of course very slow compared to the equivalent sql, but hey, it works.
scope :translations_not_in_english, ->(calmapp_version_id, language_iso_code){
join_to_cavs_tls_arr(calmapp_version_id).
joins_to_tl_arr.
where{ tl1.iso_code == 'en' }.
where{ cavtl1.calmapp_version_id == my{calmapp_version_id}}.
where{ dot_key_code << (Translation.
join_to_cavs_tls_arr(calmapp_version_id).
joins_to_tl_arr.
where{ tl1.iso_code == my{language_iso_code} }.
select{ "dot_key_code" }.all)}
}
The first 2 methods in the scope are other scopes which declare the aliases cavtl1 and tl1. << is the not in operator in squeel.
Hope this helps someone.
If someone want to use two or more conditions, you can do that:
your_array = [1,2,3,4]
your_string = "SOMETHING"
YourModel.where('variable1 NOT IN (?) AND variable2=(?)',Array.wrap(your_array),your_string)
I currently have two active record queries that I would like to combine together
joins("join relationships ON user_id = followed_id").
where("follower_id = #{user.id}")
and
where(:user_id => user.id)
Basically I want the results of the second one to appear with the first similar to a UNION statement in SQL. Can it be done in ActiveRecord in this way?
I would prefer to use a union rather that have to join all the followed_ids in a string and use the IN clause in sql.
Any ideas?
-----Edit------
I am looking for a way to get this to work with lazy loading
This was useful for me:
Model.where(...) | Model.where(...)
Use relation & relation:
Model.joins("join relationships ON user_id = followed_id").where("follower_id = {user.id}") & Model.where(:user_id => user.id)
This was useful for me:
An updated version of Rails/ActiveRecord may support this syntax natively. It would look similar to:
Model.where(foo: 'bar').or.where(bar: 'bar')
Or you can, simply sticking with the following works great:
Model.where('foo= ? OR bar= ?', 'bar', 'bar')
referred to this link
I need an SQL statement that check if one condition is satisfied:
SELECT * FROM my_table WHERE my_table.x=1 OR my_table.y=1
I want to do this the 'Rails 3' way. I was looking for something like:
Account.where(:id => 1).or.where(:id => 2)
I know that I can always fallback to sql or a conditions string. However, in my experience this often leads to chaos when combining scopes. What is the best way to do this?
Another related question, is how can describe relationship that depends on an OR condition. The only way I found:
has_many :my_thing, :class_name => "MyTable", :finder_sql => 'SELECT my_tables.* ' + 'FROM my_tables ' +
'WHERE my_tables.payer_id = #{id} OR my_tables.payee_id = #{id}'
However, these again breaks when used in combinations. IS there a better way to specify this?
Account.where(id: [1,2]) no explanation needed.
This will works in Rails 5, see rails master :
Post.where('id = 1').or(Post.where('id = 2'))
# => SELECT * FROM posts WHERE (id = 1) OR (id = 2)
For Rails 3.0.4+:
accounts = Account.arel_table
Account.where(accounts[:id].eq(1).or(accounts[:id].eq(2)))
Those arel queries are unreadable to me.
What's wrong with a SQL string? In fact, the Rails guides exposes this way as the first way to make conditions in queries: http://guides.rubyonrails.org/active_record_querying.html#array-conditions
So, I bet for this way to do it as the "Rails way":
Account.where("id = 1 OR id = 2")
In my humble opinion, it's shorter and clearer.
Sadly, the .or isn't implemented yet (but when it is, it'll be AWESOME).
So you'll have to do something like:
class Project < ActiveRecord::Base
scope :sufficient_data, :conditions=>['ratio_story_completion != 0 OR ratio_differential != 0']
scope :profitable, :conditions=>['profit > 0']
That way you can still be awesome and do:
Project.sufficient_data.profitable
I'd go with the IN clause, e.g:
Account.where(["id in (?)", [1, 2]])
I've used the Squeel gem (https://github.com/ernie/squeel/) to do OR queries and it works beautifully.
It lets you write your query as Account.where{(id == 1) | (id == 2)}
You can define an Array as value in the :conditions Hash.
So you could do for example:
Account.all(:conditions => { :id => [1, 2] })
Tested with Rails 3.1.0
Alternate syntax using Hash
Account.where("id = :val1 OR id = :val2", val1: 1, val2: 2).
This is particularly useful, when the value is compared with multiple columns. eg:
User.where("first_name = :name OR last_name = :name", name: 'tom')
With rails_or, you could do it like:
Account.where(id: 1).or(id: 2)
(It works in Rails 4 and 5, too.)
With :limit in query, I will get first N records. What is the easiest way to get last N records?
This is the Rails 3 way
SomeModel.last(5) # last 5 records in ascending order
SomeModel.last(5).reverse # last 5 records in descending order
Updated Answer (2020)
You can get last N records simply by using last method:
Record.last(N)
Example:
User.last(5)
Returns 5 users in descending order by their id.
Deprecated (Old Answer)
An active record query like this I think would get you what you want ('Something' is the model name):
Something.find(:all, :order => "id desc", :limit => 5).reverse
edit: As noted in the comments, another way:
result = Something.find(:all, :order => "id desc", :limit => 5)
while !result.empty?
puts result.pop
end
new way to do it in rails 3.1 is SomeModel.limit(5).order('id desc')
For Rails 5 (and likely Rails 4)
Bad:
Something.last(5)
because:
Something.last(5).class
=> Array
so:
Something.last(50000).count
will likely blow up your memory or take forever.
Good approach:
Something.limit(5).order('id desc')
because:
Something.limit(5).order('id desc').class
=> Image::ActiveRecord_Relation
Something.limit(5).order('id desc').to_sql
=> "SELECT \"somethings\".* FROM \"somethings\" ORDER BY id desc LIMIT 5"
The latter is an unevaluated scope. You can chain it, or convert it to an array via .to_a. So:
Something.limit(50000).order('id desc').count
... takes a second.
For Rails 4 and above version:
You can try something like this If you want first oldest entry
YourModel.order(id: :asc).limit(5).each do |d|
You can try something like this if you want last latest entries..
YourModel.order(id: :desc).limit(5).each do |d|
Solution is here:
SomeModel.last(5).reverse
Since rails is lazy, it will eventually hit the database with SQL like: "SELECT table.* FROM table ORDER BY table.id DESC LIMIT 5".
If you need to set some ordering on results then use:
Model.order('name desc').limit(n) # n= number
if you do not need any ordering, and just need records saved in the table then use:
Model.last(n) # n= any number
In my rails (rails 4.2) project, I use
Model.last(10) # get the last 10 record order by id
and it works.
Just try:
Model.order("field_for_sort desc").limit(5)
we can use Model.last(5) or Model.limit(5).order(id: :desc) in rails 5.2
I find that this query is better/faster for using the "pluck" method, which I love:
Challenge.limit(5).order('id desc')
This gives an ActiveRecord as the output; so you can use .pluck on it like this:
Challenge.limit(5).order('id desc').pluck(:id)
which quickly gives the ids as an array while using optimal SQL code.
Let's say N = 5 and your model is Message, you can do something like this:
Message.order(id: :asc).from(Message.all.order(id: :desc).limit(5), :messages)
Look at the sql:
SELECT "messages".* FROM (
SELECT "messages".* FROM "messages" ORDER BY "messages"."created_at" DESC LIMIT 5
) messages ORDER BY "messages"."created_at" ASC
The key is the subselect. First we need to define what are the last messages we want and then we have to order them in ascending order.
If you have a default scope in your model that specifies an ascending order in Rails 3 you'll need to use reorder rather than order as specified by Arthur Neves above:
Something.limit(5).reorder('id desc')
or
Something.reorder('id desc').limit(5)
A simple answer would be:
Model.limit(5).order(id: :desc)
There is a problem with this solution, as id can't be the sole determiner of when a record was created in the time.
A more reliable solution would be:
Model.order(created_at: :desc).limit(5)
As others have pointed out, one can also use Model.last(5). The only gotcha with this is that it returns Array, and not Model::ActiveRecord_Relation.
Add an :order parameter to the query