How can I minimize SQL queries

Rails
#1

I have users, who have friends that are also users in mysql database.

I have a foreign key for both users, so that I can reference their data
directly. My problem is displaying friends. My for statement would
look something like this:

for i in([email protected])
puts @user.friends[i].user.name
end

so @user is the user that i’m displaying friends for… .friends are the
entries that he is in… then .user are the users connected to him in
the database, and .name would be their name. But if a user has 200
friends then the for statement will loop through that statement 200
times and do 200 queries to grab the name. How can I grab all of the
usernames in one SQL statement utilizing my fk relationships?

thanks,
Ben

#2

Get all your users and their friends:

User.find(:all, :include => [“friends”])

Assuming that your relationships are setup correctly in your models.

~ Ben

#3

Ben R. wrote:

Get all your users and their friends:

User.find(:all, :include => [“friends”])

Assuming that your relationships are setup correctly in your models.

~ Ben

Yep, that’s exactly what I was looking for. Thanks Ben. For anyone
else who wants to know how to do a grab of 200 items in one statement
using Rails, check these out:

Eager Loading of Associations:
http://rubyonrails.org/api/classes/ActiveRecord/Associations/ClassMethods.html

and a little documentation on include:
http://rubyonrails.org/api/classes/ActiveRecord/Base.html

-Ben L.