Simple search in the database - ruby-on-rails

Question

I have a problem with a simple browser in my application.
I have already looked for solutions but still displays the following error:
param is missing or the value is empty: expense.
Please help.
Index:
<%= form_tag expenses_path :method => 'get' do %>
<%= text_field_tag :search, params[:search] %>
<%= submit_tag "Search" , name: nil %>
Controller:
class ExpensesController < ApplicationController
before_action :set_expense, only: [:show, :edit, :update, :destroy]
# GET /expense expense
# GET /expense.json
def index
#expenses = Expense.search(params[:search])
end
# GET /expense/1
# GET /expense/1.json
def show
end
# GET /expense/new
def new
#expense = Expense.new
end
# GET /expense/1/edit
def edit
end
# POST /expense
# POST /expense.json
def create
#expense = Expense.new(expense_params)
respond_to do |format|
if #expense.save
format.html { redirect_to #expense, notice: 'zostały zapisane.' }
format.json { render :show, status: :created, location: #expense }
else
format.html { render :new }
format.json { render json: #expense.errors, status: :unprocessable_entity }
end
end
end
# PATCH/PUT /expense/1
# PATCH/PUT /expense/1.json
def update
respond_to do |format|
if #expense.update(expense_params)
format.html { redirect_to #expense, notice: 'expense was successfully updated.' }
format.json { render :show, status: :ok, location: #expense }
else
format.html { render :edit }
format.json { render json: #expense.errors, status: :unprocessable_entity }
end
end
end
# DELETE /expense/1
# DELETE /expense/1.json
def destroy
#expense.destroy
respond_to do |format|
format.html { redirect_to #expense, notice: 'Zakupy zostały usunięte.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_expense
#expense = Expense.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def expense_params
params.require(:expense).permit(:date, :price, :category, :where)
end
Expense.rb:
class Expense < ApplicationRecord
def self.search(search)
if search
where (['where LIKE ?',"%#{search}%"])
else
all
end
end

Answer 1

permit the search in your params
def expense_params
params.require(:expense).permit(:date, :price, :category, :where, :search)
end
please correct the form_tag syntax
<%= form_tag(expenses_path,method: :get) do %>
<%= text_field_tag :search, params[:search] %>
<%= submit_tag "Search" , name: nil %>
<% end %>

Answer 2

The error message you report is most likely coming from your expense_params method:
params.require(:expense) means you expect the parameters to be of the form params[:expense][:date], params[:expense][:price], etc.
My best guess is that your form is not actually submitting a GET request and so it's going to the create method rather than the index method.
I think this may be occurring because you are missing a comma between expenses_path and :method => 'get' in your form_tag. It should be:
<%= form_tag expenses_path, :method => 'get' do %>