Join query in rails


#1

Hi…
how i should write the below query in rails.i found through mysql
tutorial.i m not pro in rails …so give some lights…

SELECT * FROM contactinfo join userinfo on contactinfo.contact_id =
userinfo.id where contactinfo.user_id = 25

Thanks in advance


#2

On Thu, Apr 9, 2009 at 12:40 PM, Newb N.
removed_email_address@domain.invalid wrote:

Hi…
how i should write the below query in rails.i found through mysql
tutorial.i m not pro in rails …so give some lights…

SELECT * FROM contactinfo join userinfo on contactinfo.contact_id =
userinfo.id where contactinfo.user_id = 25

Thanks in advance

It would all depend on the models you’re using.
That db schema is not technically Rails friendly in that the table
names should be user_infos and contact_infos resulting in models named
UserInfo and ContactInfo
Then you could use the following:

model ContactInfo
has_one :user_info
#or has_many :user_infos
end

model UserInfo
belongs_to :contact_info
end

and then…

contact_info = ContactInfo.new 25
user_info = contact_info.user_info

Rails deals with all the sql in the background :slight_smile:

Andrew T.
http://ramblingsonrails.com
http://www.linkedin.com/in/andrewtimberlake

“I have never let my schooling interfere with my education” - Mark Twain


#3

Newb N. wrote:

Hi…
how i should write the below query in rails.i found through mysql
tutorial.i m not pro in rails …so give some lights…

SELECT * FROM contactinfo join userinfo on contactinfo.contact_id =
userinfo.id where contactinfo.user_id = 25

Thanks in advance

@contactinfo= Contactinfo.find(:all, :joins => “contactinfos inner join
userinfos as u on contactinfos.contact_id=u.id”, :conditions =>
[“contactinfos.contact_id =?”, 25])


#4

Priya B. wrote:

Newb N. wrote:

Hi…
how i should write the below query in rails.i found through mysql
tutorial.i m not pro in rails …so give some lights…

SELECT * FROM contactinfo join userinfo on contactinfo.contact_id =
userinfo.id where contactinfo.user_id = 25

Thanks in advance

@contactinfo= Contactinfo.find(:all, :joins => “contactinfos inner join
userinfos as u on contactinfos.contact_id=u.id”, :conditions =>
[“contactinfos.contact_id =?”, 25])

Thanks for the reply…
using this query i can able to get only the contactinfo table fields but
i want to get userinfo table fields as well as contactinfo fields
also…

how can i get that…
pls guide me on this


#5

i think this is the way you should write like this… as i am also new
to
rails

ContactInfo.find(:all, :join => user_info)

On Thu, Apr 9, 2009 at 4:10 PM, Newb N.


#6

You can use :select option in the same query…


#7

On Thu, Apr 9, 2009 at 3:14 PM, Newb N.
removed_email_address@domain.invalid wrote:

Thanks in advance
how can i get that…
pls guide me on this

Don’t think of merging them into one result set, think of them as two
seperate sets of data (or models) that are related.
That’s the way Rails treats the data and it works very well.

I understand that you’re new to Rails but take some time to get to
understand Rails way of doing things and your life will be much
easier.

Andrew T.
http://ramblingsonrails.com
http://www.linkedin.com/in/andrewtimberlake

“I have never let my schooling interfere with my education” - Mark Twain


#8

Priya B. wrote:

You can use :select option in the same query…

yes priya i used but i get error …it gives me unknown column

could you give the sample

@contactinfo= ContactInfo.find(:all,:select =>
“userinfo.first_name,contactinfo.user_id”, :joins => “contactinf inner
join
userinfo as u on contactinfo.contact_id=u.id”, :conditions =>
[“contactinfo.user_id=?”, 25])

pls help me ya

Thanks


#9

why don’t you use the build options in the framework?
specify the joins / relations in the model.
Then do
@user = User.find(params[:id]) (controller)

View:
<=% @user.contactinfo.telephone %>

or
<% for user in @users do |t| %>
<%= t.contactinfo.telefone %>
<%= t.contactinfo.fax %>

If you cant to do other types of joins, use the include option in the
controller.

On Apr 10, 10:52 am, Newb N. removed_email_address@domain.invalid