Create array of arrays from database query in rails

Question

Ive got a table which consists of two fields called follower_id and followed_id. I need to create a query which creates an array of from each row and puts that in an overall array so that the end structure looks like:

"edges": [
    ["1", "2"],
    ["1", "3"],
    ["3", "4"],
    ["3", "5"]
  ]

so far I have

 def self.including_relationships
  result={}
  result["edges"] Relationship.all.each do |relationship|
    result[""]= Relationship.select(:follower_id.to_s,:follower_id.to_s)
  #the code here is called once for each user
  # user is accessible by 'user' variable
end
  result
end

but this produces:

 edges: [
"[4, 3, 3, 4]",
"[3, 4, 3, 4]"
]

This seems like a join table. You're not supposed to query those directly. Have you looked at HABTM or has_many :through constructs? See the rails guide for associations. — Mark Thomas
– Mark Thomas, Commented Jul 8, 2015 at 22:26

Arslan Ali · Accepted Answer · 2015-07-09 06:38:27Z

2

You can use map to build an array like:

Relationship.all.map { |r| [r.follower_id.to_s, r.followed_id.to_s] }

edited Jul 9, 2015 at 6:38

answered Jul 8, 2015 at 22:32

Arslan Ali

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2 Comments

Sebastian Zeki Over a year ago

should be r.followed_id.to_s but otherwise worked. Cheers

Arslan Ali Over a year ago

In case, you see something missing in any answer, you can edit it. However, I fixed it to r.

jazzytomato · Accepted Answer · 2015-07-08 22:33:59Z

1

Try this

relationships = Relationship.all.map { |r| [r.follower_id.to_s, followed_id.to_s] }

results = {"edges": relationships }

edited Jul 8, 2015 at 22:33

answered Jul 8, 2015 at 22:28

jazzytomato

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1 Comment

Sebastian Zeki Over a year ago

I get syntax errors- unexpected : and } (although seems balanced?)

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