Rails search with multiple queries not working - ruby-on-rails

Question

I know my code is clunky, but I am trying to have a form with multiple text boxes for different columns in my GUEST database. The form is not working and all my guest entries are still listed (the list is not narrowed down by the search). If anyone could possibly point me in the correct direction that would be awesome. Also how could the guest.rb code be more concise?
Controller:
def index
#guests = Guest.all
if params[:search_first_name]
#guests = Guest.search_first_name(params[:search_first_name])
end
if params[:search_last_name]
#guests = Guest.search_last_name(params[:search_last_name])
end
if params[:search_email]
#guests = Guest.search_email(params[:search_email])
end
if params[:search_phone]
#guests = Guest.search_phone(params[:search_phone])
end
end
guest.rb
def self.search_first_name(query)
# where(:email, query) -> This would return an exact match of the query
where("first_name like ?", "%#{query}%")
end
def self.search_last_name(query)
# where(:email, query) -> This would return an exact match of the query
where("last_name like ?", "%#{query}%")
end
def self.search_email(query)
# where(:email, query) -> This would return an exact match of the query
where("email like ?", "%#{query}%")
end
def self.search_phone(query)
# where(:email, query) -> This would return an exact match of the query
where("phone like ?", "%#{query}%")
end
index.html:
<%= form_tag(guests_path, :method => "get", class: "navbar-form", id: "search-form") do %>
<div class="input-append col-sm-10">
<div class="row">
<div class="col-sm-4">
<p><%= text_field_tag :search_first_name, params[:search_first_name], placeholder: "First Name", style: "width:100%;" %></p>
<p><%= text_field_tag :search_last_name, params[:search_last_name], placeholder: "Last Name", style: "width:100%;" %></p>
</div>
<div class="col-sm-4">
<p><%= text_field_tag :search_email, params[:search_email], placeholder: "Email Address", style: "width:100%;" %></p>
<p><%= text_field_tag :search_phone, params[:search_phone], placeholder: "Phone Number", style: "width:100%;" %></p>
</div>
<div class="col-sm-4">
</div>
<%= submit_tag 'Search Guests' %>
</div>
</div>
<% end %>
<table class="table table-hover col-sm-12">
<thead>
<tr>
<th>Guest ID</th>
<th>Guest Name</th>
<th>Email</th>
<th>Phone</th>
<th></th>
</tr>
</thead>
<tbody>
<% #guests.each do |guest| %>
<tr>
<td>G-00<%= guest.id %></td>
<td><%= guest.first_name %> <%= guest.last_name %></td>
<td><%= guest.email %></td>
<td><%= guest.phone %></td>
<td style="text-align:right;"><%= link_to 'View Guest Profile', guest, :class => "btn btn-sm btn-success" %> <%= link_to 'Edit', edit_guest_path(guest), :class => "btn btn-sm btn-default" %> <%= link_to 'Destroy', guest, method: :delete, data: { confirm: 'Are you sure?' }, :class => "btn btn-sm btn-danger" %></td>
</tr>
<% end %>
</tbody>
</table>

Answer 1

The problem comes because a param without a value will be equal to "" which is still true in Ruby, so basically if your search_phone is ever empty then you'll see all the results because if params[:search_phone] will be true and so that block will be run, and the eventual code that's run will be equivalent to:
#guests = Guest.where( "phone like '%%'" )
Which is just two wildcards, and will therefore return all results. Other people have already mentioned changing that conditional to use .present? so it won't be run if it's blank.
You also asked about refactoring the code, I would write it like so:
controller
def index
#guests = Guest.search_or_all params
end
model
def self.search_or_all params={}
query = %i[first_name last_name email phone].map do |k|
kk = "search_#{k}"
sanitize_sql ["#{k} LIKE '%s'", "%#{params[kk]}%"] if params[kk]
end.compact.join " OR "
where query
end

Answer 2

Without going deep into a code refactoring. Try adding params[:field_name].present? to all the if statements.

Answer 3

You should put "^#{query}" to make this work as a regular expression.
This way your Guest.rb file will look like this
Guest.rb
def self.search_first_name(query)
# where(:email, query) -> This would return an exact match of the query
where("first_name like ?", "^#{query}")
end
def self.search_last_name(query)
# where(:email, query) -> This would return an exact match of the query
where("last_name like ?", "^#{query}")
end
def self.search_email(query)
# where(:email, query) -> This would return an exact match of the query
where("email like ?", "")
end
def self.search_phone(query)
# where(:email, query) -> This would return an exact match of the query
where("phone like ?", "%#{query}%")
end