Module: Que::Migrations

Defined in:
lib/que/migrations.rb

Constant Summary collapse

CURRENT_VERSION =

In order to ship a schema change, add the relevant up and down sql files to the migrations directory, and bump the version here.

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Class Method Summary collapse

Class Method Details

.db_version ⇒ Object 



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# File 'lib/que/migrations.rb', line 38

def db_version
  result =
    Que.execute "      SELECT relname, description\n      FROM pg_class\n      LEFT JOIN pg_description ON pg_description.objoid = pg_class.oid\n      WHERE relname = 'que_jobs'\n    SQL\n\n  if result.none?\n    # No table in the database at all.\n    0\n  elsif (d = result.first[:description]).nil?\n    # There's a table, it was just created before the migration system\n    # existed.\n    1\n  else\n    d.to_i\n  end\nend\n"

.migrate!(version:) ⇒ Object 



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# File 'lib/que/migrations.rb', line 10

def migrate!(version:)
  Que.transaction do
    current = db_version

    if current == version
      return
    elsif current < version
      direction = :up
      steps = ((current + 1)..version).to_a
    elsif current > version
      direction = :down
      steps = ((version + 1)..current).to_a.reverse
    end

    steps.each do |step|
      filename = [
        File.dirname(__FILE__),
        'migrations',
        step,
        direction,
      ].join('/') << '.sql'
      Que.execute(File.read(filename))
    end

    set_db_version(version)
  end
end

.set_db_version(version) ⇒ Object 



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# File 'lib/que/migrations.rb', line 59

def set_db_version(version)
  i = version.to_i
  Que.execute "COMMENT ON TABLE que_jobs IS '#{i}'" unless i.zero?
end