Rails Model find where not equal

Question

How can I find records in my database on a not equal condition   I have this now  but is there a fancy rails-speak way of doing it   GroupUser where  user id       me

User · Answer

In Rails 3  I don t know anything fancier  However  I m not sure if you re aware  your not equal condition does not match for  user id  NULL values  If you want that  you ll have to do something like this   GroupUser where  user id      OR user id IS NULL   me

User · Answer

Rails 4   If you want to use both not equal and equal  you can use   user id   4 group id   27 GroupUser where group id  group id  where not user id  user id    If you want to use a variety of operators  ie   gt    lt    at some point you may want to switch notations to the following   GroupUser where  group id  gt    AND user id        group id  user id

User · Answer

Rails 4  GroupUser where not user id  me

User · Answer

The only way you can get it fancier is with MetaWhere    MetaWhere has a newer cousin which is called Squeel which allows code like this   GroupUser where user id    me    It goes without saying  that if this is the only refactor you are going to make  it is not worth using a gem and I would just stick with what you got  Squeel is useful in situations where you have many complex queries interacting with Ruby code

User · Answer

In Rails 4 x  See http   edgeguides rubyonrails org active record querying html not-conditions   GroupUser where not user id  me    In Rails 3 x  GroupUser where GroupUser arel table  user id  not eq me     To shorten the length  you could store GroupUser arel table in a variable or if using inside the model GroupUser itself e g   in a scope  you can use arel table  user id  instead of GroupUser arel table  user id   Rails 4 0 syntax credit to  jbearden s answer

User · Answer

You should always include the table name in the SQL query when dealing with associations   Indeed if another table has the user id column and you join both tables  you will have an ambiguous column name in the SQL query  i e  troubles    So  in your example   GroupUser where  groups users user id        me    Or a bit more verbose   GroupUser where    table name  user id IS NOT     me    Note that if you are using a hash  you don t need to worry about that because Rails takes care of it for you   GroupUser where user  me    In Rails 4  as said by  dr4k3  the query method not has been added   GroupUser where not user  me

[ruby-on-rails] Rails Model find where not equal

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