How do I create an array from columns?

Question

How do I create an array from database columns?

My table Reklamer:

id  virksomhed  dato                   klik     
10  Iqmedier    2011-02-15 00:00:00     4   
11  Iqmedier    2011-02-15 00:00:00     2   
12  Iqmedier    2011-02-15 00:00:00     3

I want to create an array of all the columns klik. Like [4, 2, 3]

An can someone explain what a block and an object is :) Or where I can read something about it.

@Rails beginner, FYI, on StackOverflow they discourage using greetings (salutations), signatures and thanking people in advance or "best regards" and similar (validictions). — the Tin Man
– the Tin Man, Commented Feb 16, 2011 at 21:36
And they also discourage having "Simple qu[e]stion" in the question title. — Andrew Grimm
– Andrew Grimm, Commented Feb 16, 2011 at 22:04

Dogbert · Accepted Answer · 2011-02-16 21:05:05Z

1

I'm guessing you have a model named Reklamer too.

You can do the following to get the array

Reklamer.select('klik').all.map(&:klik)

Edit:

(Array.map in Ruby) map(&:klik) is just a shorthand for

.map do |record|
  record.klik
end

It returns the value of klik for each record, and creates a new array using those values.

edited Feb 16, 2011 at 21:05

answered Feb 16, 2011 at 20:57

Dogbert

224k43 gold badges419 silver badges416 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Rails beginner Over a year ago

What does .map(&:klik)? Does it create an array?

Rails beginner Over a year ago

How do i only create an array of those were the column Virksomhed = Iqmedier. I have tried with this data: <%= Reklamer.select(:all, :conditions => {:virksomhed => 'Iqmedier'}).select('earn').all.map(&:earn) %> But gets a error: wrong number of arguments (2 for 1)

Dogbert Over a year ago

Try Reklamer.where(:virksomhed => 'Iqmedier').all.map(&:earn)

Collectives™ on Stack Overflow

How do I create an array from columns?

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related