Inspirado por esta resposta , criamos o seguinte
database.rake
Arquivo. Onde a resposta original funcionou apenas para o PostgreSQL 9.1, esta foi modificada para funcionar também para o PostgreSQL 9.2. O mecanismo não é o mais bonito:quando o comando 9.1 falha, ele simplesmente executa o comando 9.2. Mas o mais importante:funciona! #{Rails.root}/lib/tasks/databases.rake
# monkey patch ActiveRecord to avoid There are n other session(s) using the database.
def drop_database(config)
case config['adapter']
when /mysql/
ActiveRecord::Base.establish_connection(config)
ActiveRecord::Base.connection.drop_database config['database']
when /sqlite/
require 'pathname'
path = Pathname.new(config['database'])
file = path.absolute? ? path.to_s : File.join(Rails.root, path)
FileUtils.rm(file)
when /postgresql/
begin
ActiveRecord::Base.establish_connection(config.merge('database' => 'postgres', 'schema_search_path' => 'public'))
ActiveRecord::Base.connection.select_all("select * from pg_stat_activity order by procpid;").each do |x|
if config['database'] == x['datname'] && x['current_query'] =~ /<IDLE>/
ActiveRecord::Base.connection.execute("select pg_terminate_backend(#{x['procpid']})")
end
end
ActiveRecord::Base.connection.drop_database config['database']
rescue # in PG 9.2 column procpid was renamed pid and the query status is checked not using 'current_query' but using 'state'
ActiveRecord::Base.establish_connection(config.merge('database' => 'postgres', 'schema_search_path' => 'public'))
ActiveRecord::Base.connection.select_all("select * from pg_stat_activity order by pid;").each do |x|
if config['database'] == x['datname'] && x['state'] =~ /idle/
ActiveRecord::Base.connection.execute("select pg_terminate_backend(#{x['pid']})")
end
end
ActiveRecord::Base.connection.drop_database config['database']
end
end
end