How to list of all the tables defined for the database when using active record?
ActiverecordActiverecord Problem Overview
How do I get a list of all the tables defined for the database when using active record?
Activerecord Solutions
Solution 1 - Activerecord
Call http://github.com/rails/rails/tree/master/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb#L21"><code>ActiveRecord::ConnectionAdapters::SchemaStatements#tables</code></a>;. This method is undocumented in the MySQL adapter, but is documented in the PostgreSQL adapter. SQLite/SQLite3 also has the method implemented, but undocumented.
>> ActiveRecord::Base.connection.tables
=> ["accounts", "assets", ...]
See http://github.com/rails/rails/tree/master/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb#L21"><code>activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb:21</code></a>;, as well as the implementations here:
- http://github.com/rails/rails/tree/master/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb#L412"><code>activerecord/lib/active_record/connection_adapters/mysql_adapter.rb:412</code></a>
- http://github.com/rails/rails/tree/master/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb#L615"><code>activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:615</code></a>
- http://github.com/rails/rails/tree/master/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb#L176"><code>activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb:176</code></a>
Solution 2 - Activerecord
Based on the two previous answers, you could do:
ActiveRecord::Base.connection.tables.each do |table|
next if table.match(/\Aschema_migrations\Z/)
klass = table.singularize.camelize.constantize
puts "#{klass.name} has #{klass.count} records"
end
to list every model that abstracts a table, with the number of records.
Solution 3 - Activerecord
> An update for Rails 5.2
For Rails 5.2 you can also use ApplicationRecord to get an Array with your table' names. Just, as imechemi mentioned, be aware that this method will also return ar_internal_metadata and schema_migrations in that array.
ApplicationRecord.connection.tables
Solution 4 - Activerecord
It seems like there should be a better way, but here is how I solved my problem:
Dir["app/models/*.rb"].each do |file_path|
require file_path # Make sure that the model has been loaded.
basename = File.basename(file_path, File.extname(file_path))
clazz = basename.camelize.constantize
clazz.find(:all).each do |rec|
# Important code here...
end
end
This code assumes that you are following the standard model naming conventions for classes and source code files.
Solution 5 - Activerecord
Don't know about active record, but here's a simple query:
select table_name from INFORMATION_SCHEMA.Tables where TABLE_TYPE = 'BASE TABLE'