Trying to search by first_name and last_name - ruby-on-rails

Question

I am trying to search a user by both first and last name in my rails app and am currently getting mixed results for each method I try. Is there a way to re-write any of these methods to get my desired results?
user_controller.rb
method #1
def self.search(query)
where("first_name LIKE ? OR last_name LIKE ?", "%#{query}%", "%#{query}%")
end
This works for either first or last name but not both.
Method #2
def self.search(keywords)
if keywords
where(:all, :conditions => ["concat(first_name," ",last_name) like?", "%#{keywords}%"])
end
end
This doesn't return any result
Method#3
def self.search(search)
if search
select('(first_name || " " || last_name) as \'ful_name\', *')
where ['first_name LIKE :s OR last_name LIKE :s OR ful_name LIKE :s', :s => "%#{search}"]
else
scoped
end
end
This returns the error
SQLite3::SQLException: no such column: ful_name: SELECT "users".* FROM "users" WHERE (first_name LIKE '%Spider Man' OR last_name LIKE '%Spider Man' OR ful_name LIKE '%Spider Man') ORDER BY created_at DESC
app/views/users/index.html.erb:5:in `_app_views_users_index_html_erb__848623016_40254132'
index.html.erb
<% provide(:title, 'Search') %>
<h1>Search</h1>
<ul class="span4 users">
<%= render #users %>
</ul>
_user.html.erb
<li>
<%= image_tag user.avatar(:medium) %>
<h4><%= link_to user.full_name, feed_user_path(user), :class => "follow-color" %></h4>
<% if current_user.admin? && !current_user?(user) %>
| <%= link_to "delete", user, method: :delete,
data: { confirm: "You sure?" } %>
<% end %>
</li>
_header.html.erb
<%= form_tag users_path, method: "get", class: "search-bar" do %>
<%= text_field_tag :search, params[:search], placeholder: "Search" %>
<% end %>

Answer 1

This one:
:conditions => ["concat(first_name," ",last_name) like?", "%#{keywords}%"]
won't work because you have an (insidious) quote problem. In Ruby, this:
"a" "b"
is the same as:
"ab"
so your :conditions is really this:
:conditions => ["concat(first_name,,last_name) like?", "%#{keywords}%"]
You mean to say:
:conditions => ["concat(first_name, ' ', last_name) like ?", "%#{keywords}%"]
String literals in SQL use single quotes, not double quotes. Also, if you're using a database that claims to support standard SQL, you should use the || operator for string concatenation:
:conditions => ["first_name || ' ' || last_name like ?", "%#{keywords}%"]
The third one won't work because aliases defined in a SELECT clause are not generally available in the WHERE clause, hence the "unknown column" error. You're also throwing away the result of the select call so I think you're missing a . in here too:
select('(first_name || " " || last_name) as \'ful_name\', *')
where ['first_name LIKE :s OR last_name LIKE :s OR ful_name LIKE :s', :s => "%#{search}"]
There's also a potential quoting problem: string literals use single quotes in SQL, double quotes are for identifiers. You want to say just:
where("first_name like :s or last_name like :s or first_name || ' ' || last_name like :s", :s => "%#{search}")
or just:
where("first_name || ' ' || last_name like :s", :s => "%#{search}")
A couple caveats:
String concatenation operators are database-specific. Standard SQL uses || but, depending on the configuration, MySQL wants to use the concat function. AFAIK, SQLite supports a lot of MySQL-isms but you need to be aware when you're using them and you should stick to the standard as much as possible.
Quoting is, again, database-specific. Standard SQL uses single quotes for string literals and double quotes for identifiers (such as table and column names). MySQL uses back-ticks for identifiers, SQLite (AFAIK) lets you use double quotes or back-ticks for identifiers and single or double quotes for strings. Again, stick to the standard as much as possible to build good habits.

Answer 2

I wanted to do the same, i followed this good tuto : https://www.youtube.com/watch?v=s88Uc0InOAM
Then i had the same problem u have, i wanted to search in both name and surname.
Here it's what i did and it's working :
#indiens = Indien.where("name LIKE ?", "%" + params[:q] + "%" ).or(Indien.where("surname LIKE ?", "%" + params[:q] + "%" ))
It may be possible to chain more, but i didn't test.
I know it has been 5 year, maybe it will help others.