scenic-views/scenic · error · RuntimeError

Define view query in #{path} before migrating.

Error message

Define view query in #{path} before migrating.

What it means

Scenic resolves each view's SQL from db/views/<name>_vNN.sql (version zero-padded to two digits) under Rails.root. Definition#to_sql reads that file and raises RuntimeError ('Define view query in <path> before migrating.') when the content is empty. The scenic:view generator deliberately scaffolds an empty stub for you to fill in, and migrating before writing the SELECT into it triggers this. A missing file raises Errno::ENOENT instead - this message means the file exists but has zero bytes.

Source

Thrown at lib/scenic/definition.rb:12

module Scenic
  # @api private
  class Definition
    def initialize(name, version)
      @name = name.to_s
      @version = version.to_i
    end

    def to_sql
      File.read(full_path).tap do |content|
        if content.empty?
          raise "Define view query in #{path} before migrating."
        end
      end
    end

    def full_path
      Rails.root.join(path)
    end

    def path
      File.join("db", "views", filename)
    end

    def version
      @version.to_s.rjust(2, "0")
    end

    private

View on GitHub (pinned to f2162dbddb)

Solutions

1. Open the exact path named in the message and write the view query (for example: SELECT id, email FROM users WHERE active;)
2. If the version file was never created, run rails g scenic:view <name> (add --materialized for matviews), fill the stub, then migrate
3. If content was lost in a merge or sync, recover it from git history: git log --oneline -- db/views/searches_v01.sql and restore the last non-empty revision

Example fix

# before: db/views/searches_v01.sql exists but is empty
# migration => Define view query in db/views/searches_v01.sql before migrating.

# after: db/views/searches_v01.sql
SELECT id, email FROM users WHERE active;

Dir[Rails.root.join('db/views/*.sql')].each do |f|
  abort f + ' is empty; fill in the view query before migrating' if File.read(f).strip.empty?
end

When it happens

Trigger: Running rails g scenic:view searches followed by db:migrate without editing db/views/searches_v01.sql; bumping to create_view :searches, version: 2 while db/views/searches_v02.sql is empty; a definition file truncated to zero bytes by a bad merge, editor crash, or file-sync tool.

Common situations: Committing the generated stub so CI's migration job hits it; a merge conflict resolved by keeping an empty side; definition files emptied by sync or filter processes (LFS, Docker copy, formatting hooks).

Related errors

• #{method} is reversible only if given a revert_to_version
• a transaction is required to perform a side-by-side update
• version is required
• Materialized views require Postgres 9.3 or newer
• Cannot replace materialized views

AI-assisted analysis of scenic-views/scenic@f2162dbddb (2026-08-23). Data as JSON: /api/errors/79ca1a13277dfa4c. Report an issue: GitHub.