Activerecord Select Except Columns

ActiveRecord select except columns

write a scope like

def select_without columns
  select(column_names - columns.map(&:to_s))
end

Specify fields to exclude from Rails query result

You could use:

Client.select(Client.column_names - ["name", "some_other_column"])

Edit: Rails 5 also introduced ignored_columns if you want to exclude columns by default.

https://github.com/rails/rails/pull/21720
https://api.rubyonrails.org/classes/ActiveRecord/ModelSchema/ClassMethods.html#method-i-ignored_columns-3D

ActiveRecord find and only return selected columns

In Rails 2

l = Location.find(:id => id, :select => "name, website, city", :limit => 1)

...or...

l = Location.find_by_sql(:conditions => ["SELECT name, website, city FROM locations WHERE id = ? LIMIT 1", id])

This reference doc gives you the entire list of options you can use with .find, including how to limit by number, id, or any other arbitrary column/constraint.

In Rails 3 w/ActiveRecord Query Interface

l = Location.where(["id = ?", id]).select("name, website, city").first

Ref: Active Record Query Interface

You can also swap the order of these chained calls, doing .select(...).where(...).first - all these calls do is construct the SQL query and then send it off.

Ignoring certain field when querying in Rails and ActiveRecord

Model#attribute_names should return array of columns/attributes. You can exclude some of them and pass to pluck or select methods.

Something like this:

posts = Post.where(published: true).select(Post.attribute_names - ['enormous_field'])

Rails ActiveRecord query ForeignKey except column

You need to pass the except option as part of the addresses key:

Users.all.to_json(
  include: {
    addresses: {
      except: :country
    }
  }
)

How to select only specific columns when querying using ActiveRecord?

In your post model you can define the association as follows:

belongs_to :user, :select => [:username]

Then referring to the user via a post would select only the stated columns.

Active record is not returning specific columns when using model.find

That's because you have serializer or custom as_json method for your model and you lack the field

How to mark a column for deletion or exclude in ActiveRecord PostgreSQL?

I've found the answer in Rails docs, there ignored_columns that needs to be set: https://api.rubyonrails.org/classes/ActiveRecord/ModelSchema/ClassMethods.html#method-i-ignored_columns-3D

Once the updated code is deployed, it should be safe to drop the column.

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