# Populate combo box from database without repeatness **URL:** \ **Category:** Rails\ **Created:** [September 8, 2010, 4:14pm UTC](https://www.ruby-forum.com/t/populate-combo-box-from-database-without-repeatness/194657 "2010-09-08T16:14:32Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![PalaniKannan\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/eb8c5e/32.png) [@PalaniKannan\_K](https://www.ruby-forum.com/u/PalaniKannan_K)\ **Post date:** [September 8, 2010, 4:14pm UTC](https://www.ruby-forum.com/t/populate-combo-box-from-database-without-repeatness/194657/1 "2010-09-08T16:14:32Z")
Hi, I have a column of data with repeated as mentioned below. _column\_name_ Acer Lenova HP Lenova Acer Acer Lenova I need to populate this column in a combo box without repeated data as mentioned below _combo box_ Acer Lenova HP I tried as \<%= collection\_select(:column\_name, TableName.all)%\> “table\_names” is a table and “column\_name” is a column needed to populate. – With Regards Palani Kannan. K ---
**Author:** ![PalaniKannan\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/eb8c5e/32.png) [@PalaniKannan\_K](https://www.ruby-forum.com/u/PalaniKannan_K)\ **Post date:** [September 8, 2010, 5:51pm UTC](https://www.ruby-forum.com/t/populate-combo-box-from-database-without-repeatness/194657/2 "2010-09-08T17:51:25Z")
a. Get your DB Access out of the views… b. Read The Fine Manual on collection\_select c. Controller: @vendors = TableName.find(:all).uniq or some variant thereof With a lot of records, you might want to use a find\_by\_sql and let the DB do the work with a “SELECT DISTINCT…” d. View: \<%= collection\_select(“model\_to\_populate”, “column\_to\_populate”, @vendors, “id”, “vendor\_name\_field”) %\> ---
**Author:** ![PalaniKannan\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/eb8c5e/32.png) [@PalaniKannan\_K](https://www.ruby-forum.com/u/PalaniKannan_K)\ **Post date:** [September 9, 2010, 12:04pm UTC](https://www.ruby-forum.com/t/populate-combo-box-from-database-without-repeatness/194657/3 "2010-09-09T12:04:43Z")
Hi, Ar Chron, It works… Thank you for kind help. But, I am unable to use params[:id] to get the selected value from collection\_select. how i can get selected value to params. I need the flow collection\_select (value selected) → param[:id]-\> find SQL row… On 8 September 2010 17:51, Ar Chron [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > To post to this group, send email to removed\_email\_address@domain.invalid. > To unsubscribe from this group, send email to > removed\_email\_address@domain.invalid[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > . > For more options, visit this group at > [http://groups.google.com/group/rubyonrails-talk?hl=en](http://groups.google.com/group/rubyonrails-talk?hl=en). – With Regards Palani Kannan. K Office: +49-531-2616-226 Mobile: +4917647098166 ---
**Author:** ![PalaniKannan\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/eb8c5e/32.png) [@PalaniKannan\_K](https://www.ruby-forum.com/u/PalaniKannan_K)\ **Post date:** [September 9, 2010, 4:39pm UTC](https://www.ruby-forum.com/t/populate-combo-box-from-database-without-repeatness/194657/4 "2010-09-09T16:39:01Z")
PalaniKannan K wrote: > But, I am unable to use params[:id] to get the selected value > from collection\_select. how i can get selected value to params. > > I need the flow > collection\_select (value selected) -\> param[:id]-\> find SQL row… The selected value is in params already, just not where you’re looking. Take a look in your log at the post request that rails receives when you submit the form… this information is all readily available there. You should see something like: Parameters: {“utf8”=\>“blah1”, “authenticity\_token”=\>“blah2”, “model\_to\_populate”=\>{“column\_to\_populate”=\>“blah3”,…}, “commit”=\>“blah4”, “id”=\>“blah5”} In your controller code, params[:id] is the id of the ‘model\_to\_populate’ (blah5) params[:model\_to\_populate][:column\_to\_populate] is the value stored by the collection\_select statement in the view (blah3) Parsing through and understanding your log files is something everyone should be comfortable with. It’s usually the first stop in performing triage on unexpected behaviors. ---
**Author:** ![PalaniKannan\_K](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/eb8c5e/32.png) [@PalaniKannan\_K](https://www.ruby-forum.com/u/PalaniKannan_K)\ **Post date:** [September 9, 2010, 4:47pm UTC](https://www.ruby-forum.com/t/populate-combo-box-from-database-without-repeatness/194657/5 "2010-09-09T16:47:33Z")
HI, Its populated… Thank you verymuch… On 9 September 2010 16:39, Ar Chron [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Take a look in your log at the post request that rails receives when you > > You received this message because you are subscribed to the Google G. > “Ruby on Rails: Talk” group. > To post to this group, send email to removed\_email\_address@domain.invalid. > To unsubscribe from this group, send email to > removed\_email\_address@domain.invalid[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > . > For more options, visit this group at > [http://groups.google.com/group/rubyonrails-talk?hl=en](http://groups.google.com/group/rubyonrails-talk?hl=en). – With Regards Palani Kannan. K Office: +49-531-2616-226 Mobile: +4917647098166