Does not equal conditional

I want to have a where clause with an equal and does not equal condition:

@user = User.where(:user_id => current_user.id, :author_id != current_user.id).nil? ? (render :something) : (render :somethingelse)

The above does not work:

开发者_开发百科syntax error, unexpected ')', expecting tASSOC ...d, :user_id != current_user.id).nil? ? (render :index) : (re...

If I change the second condition from != to => it will work, however.

How do I have both conditions in one where clase? Thank you

Here's how you would use Arel to generate the query "select * from users where user_id = ? and author_id != ?":

users = User.arel_table
User.where(users[:user_id].      eq(current_user.id).and(
           users[:author_id].not_eq(current_user.id)))

Using Arel isn't as concise as using Hash conditions for simple conditions, but it's a lot more powerful!

Here's a link to the full list of predications (eq, not_eq, gt, lt, etc.) available with Arel.

I believe, it should be:

@user = User.where(['user_id = ? AND author_id <> ?', current_user.id, current_user.id])
render(@user ? :something : :somethingelse)

Rails 4 has this all figured out

Model.where.not(:colname => nil)
#=> returns all records whose :colname values are not nil

The syntax error is due to you attempting to use != instead of =>. The where method does not support inequality with hashed arguments, so your not equal will need to be written using array arguments.

User.where(:user_id => current_user.id).where(['users.author_id <> ?', current_user.id])

http://guides.rubyonrails.org/active_record_querying.html#hash-conditions

Only equality, range and subset checking are possible with Hash conditions.

You'll need to either drop down to straight SQL or invert and arel query, see Is there a way to invert an ActiveRecord::Relation query?

Not sure if you're aware, the not equal condition typically does not match (author_id) NULL values. You'll have to do an OR author_id IS NULL if you want that.

@users = User.where("user_id = ? AND (author_id != ? OR author_id IS NULL)", 
                    current_user.id, current_user.id)

render(@users.present? ? :something : :somethingelse)

Also note that I'm using @users.present? because where finder returns an ActiveRecord::Relation array.