# Trying to print on the console a single column from a db **URL:** \ **Category:** Rails\ **Created:** [October 2, 2007, 10:48pm UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148 "2007-10-02T22:48:01Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 2, 2007, 10:48pm UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/1 "2007-10-02T22:48:01Z")
Trying to get a grasp on how ruby works with data, so used to perl. Here is what im trying to do in my app/models scrap.rb def self.START ``` all = MyDb.find_all_by_server_name('myserver', :limit => 1) puts all # all i get back here is the address puts all[1] # i want element 1 but i get "nil" ``` end I have a single table that has a server\_name field and it has data in it as myserver Just trying to see how i capture the elements of a row one by one and access them. From the irb i know can say find :all and it returns the row but i how do pick this data and assign the values to a usable variable?. Thanks ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 2, 2007, 10:59pm UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/2 "2007-10-02T22:59:22Z")
Since you are using :limit =\> 1 you are not going to get an array, just a single object. Remember that in ruby, the @ signifies an instance variable, and does not signify that the variable holds an array as it does in perl. This will work: def self.START ``` all = MyDb.find_all_by_server_name('myserver', :limit => 1) puts all[:server_name] ``` end ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 2, 2007, 11:06pm UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/3 "2007-10-02T23:06:24Z")
Sorry, my bad, when I first looked at this I read it as @all, but the solution is the same, you are getting a single object rather than an array. Hope this helps. ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 2, 2007, 11:19pm UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/4 "2007-10-02T23:19:52Z")
btw, you can also use accessor methods like: def self.START ``` all = MyDb.find_all_by_server_name('myserver', :limit => 1) puts all.server_name ``` end ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 2, 2007, 11:17pm UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/5 "2007-10-02T23:17:19Z")
William P. wrote: > Sorry, my bad, when I first looked at this I read it as @all, but the > solution is the same, you are getting a single object rather than an > array. Hope this helps. Thanks william, im just using streamlined framework so i wasnt sure if i was doing something wrong with it. Just need to build a command list and run system on it so its gets executed on the unix side. This is a little bit of a learning curve for me so thanks again for your help ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 3, 2007, 4:05am UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/6 "2007-10-03T04:05:22Z")
On 10/2/07, William P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Since you are using :limit =\> 1 you are not going to get an array, just > a single object. Huh? That’s not the behavior I get. I get an array with one element if I use find(:all) or find\_all\_by\_blah, with :limit =\> 1 ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 3, 2007, 7:39am UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/7 "2007-10-03T07:39:53Z")
You are right. First off, I have never tried using an find\_all\_by\_foo method with a :limit of one, but based on the output he was seeing, it looked like a single object, although looking at it again, it is a single element array. Sorry for the confusion. ---
**Author:** ![newrubyuser](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/898d66/32.png) [@newrubyuser](https://www.ruby-forum.com/u/newrubyuser)\ **Post date:** [October 3, 2007, 4:10am UTC](https://www.ruby-forum.com/t/trying-to-print-on-the-console-a-single-column-from-a-db/116148/8 "2007-10-03T04:10:03Z")
On 10/2/07, Brent B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Trying to get a grasp on how ruby works with data, so used to perl. > Here is what im trying to do in my app/models scrap.rb > > def self.START > > ``` > all = MyDb.find_all_by_server_name('myserver', :limit => 1) > > puts all # all i get back here is the address > > ``` use inspect to get a better view of what you have (it’s sorta like Data::Dumper): puts all.inspect > ``` > puts all[1] # i want element 1 but i get "nil" > > ``` > > end all[1] is the _second_ element of the array. all[0] or all.first would be the first. Also, when you use find\_all, you will get an empty array if the query doesn’t find any matches. If you just want the first match, use find\_by\_server\_name (no “all” and no :limit). That returns either a single object (if a row is found), or nil if nothing was found. row = MyModel.find\_by\_server\_name ‘myserver’ puts row.inspect HTH