IS NOT condition for rails instance variable

Question

I have a hash with members of an appointment and try to create a MySQL query in my rails controller. The users with the ids from the map command e.g. {1,3} should be excluded in the query. So for example @appointment.members.map{|m| m.user_id} returns {1,3,5} and I'd like to find all other users but these.

@users = User.where( "id NOT IN (?)", @appointment.members.map{|m| m.user_id} )

I'm using Rails 3.2.9 so maybe my exclude statement is wrong cause I don't get any result out of this query. The problem can't be the map array - I already tested that. Thanks in advance.

Thats the strange part - if I test the query in the rails console I get valid results but in the controller the @users instance variable is empty... — Nenzo
– Nenzo, Commented Dec 10, 2012 at 10:24
Is @appointment.members really a Hash or do you mean that it's a has_many relationship? — mikej
– mikej, Commented Dec 10, 2012 at 10:31

Kevin Smouts · Accepted Answer · 2012-12-10 17:55:30Z

1

I think you just have a problem with the map method, try this:

@users = User.where( "id NOT IN (?)", @appointment.members.map(&:user_id) )

EDIT: removed the wrong syntax for future readers if any

edited Dec 10, 2012 at 17:55

answered Dec 10, 2012 at 10:26

Kevin Smouts

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2 Comments

Nenzo Over a year ago

The first one returns just an empty array [], with the second one I get all users, including those in the .map array

Lee Jarvis Over a year ago

The second one is not valid. The first one is

Nenzo · Accepted Answer · 2012-12-10 12:06:22Z

0

I solved the problem with a new instance variable:

@members = @appointment.members.all

and then

@add_users = User.where( "id NOT IN (?)", @members.map(&:user_id) )

thanks for the support

answered Dec 10, 2012 at 12:06

Nenzo

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1 Comment

244an Over a year ago

Then you can do @add_users = User.where( "id NOT IN (?)", @appointment.members.all.map(&:user_id) ) directly, but you know that perhaps?

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