ActiveRecord::StatementInvalid at /category/5 - ruby

Question

I am a new developer working on a Sinatra/Ruby/ActiveRecord app. I have established a 1:many (postgres) relationship between Category and Recipe. When I try to list the recipes in a category I get the error:
ActiveRecord::StatementInvalid at /category/5
PG::UndefinedColumn: ERROR: column recipes.category_id does not exist LINE 1: SELECT 1 AS one FROM "recipes" WHERE "recipes"."category_id... ^ : SELECT 1 AS one FROM "recipes" WHERE "recipes"."category_id" = $1 LIMIT 1
file: postgresql_adapter.rb location: prepare line: 637
app.rb
get('/category/:id') do
#category = Category.find(params.fetch('id'))
#recipes = #category.recipes
erb(:category)
end
category.erb
<% if #recipes.any?() %>
<% #recipes.each() do |recipe| %>
<ul>
<li><a href='/recipe/<%=recipe.id%>'> <%=recipe.recipe_name%></a></li>
</ul>
<%end%>
<%else %>
<p>You have no recipes!</p>
<%end%>
schema
ActiveRecord::Schema.define(version: 20150930234556) do
# These are extensions that must be enabled in order to support this database
enable_extension "plpgsql"
create_table "categories", force: :cascade do |t|
t.string "cat_name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "images", force: :cascade do |t|
t.string "image_name"
t.string "url"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "alt"
t.integer "width"
t.integer "height"
t.integer "recipe_id"
end
create_table "ingredients", force: :cascade do |t|
t.string "ingredient_name"
t.integer "recipe_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "instructions", force: :cascade do |t|
t.string "instruction_name"
t.integer "recipe_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "recipes", force: :cascade do |t|
t.string "recipe_name"
t.string "source"
t.string "servings"
t.string "comment"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "cat_id"
end
end
I have searched my project folders and cannot find category_id. Don't know why it's looking for that, my field names are category.id and recipe.cat_id.

Answer 1

This:
#recipes = #category.recipes
suggests that you have
has_many :recipes
in your Category model. That has_many will be looking for a category_id column in your recipes table (i.e. a category_id attribute in your Recipe model). But you don't have a recipes.category_id column, you have a recipes.cat_id column:
create_table "recipes", force: :cascade do |t|
#...
t.integer "cat_id"
end
I'd recommend renaming the recipes.cat_id column to recipes.category_id to match the conventions that Rails has a very strong preference for. If you can't rename the column then add a :foreign_key option to that has_many to tell Category how to resolve the relationship:
has_many :recipes, :foreign_key => :cat_id