ActiveRecord ↔︎ Sequel raw sql cheat sheet
UPDATED with fixes from @jeremyevans
Going back and forth between ActiveRecord and Sequel can be very confusing... especially because the Sequel documentation assumes that you use "datasets" instead of raw sql.
| What | ActiveRecord | Sequel |
|---|---|---|
| One value | ActiveRecord::Base.connection.select_value(sql) |
DB[sql].get |
| One row as hash | ActiveRecord::Base.connection.select_one(sql) |
DB[sql].first |
| One column across many rows | ActiveRecord::Base.connection.select_values(sql) |
DB[sql].select_map |
Many rows as hashes | ActiveRecord::Base.connection.select_all(sql) |
DB[sql].all |
| Quote value | ActiveRecord::Base.connection.quote(value) |
DB.literal(value) |
| Quote identifier (e.g. table name, column name) | ActiveRecord::Base.connection.quote_ident(ident) |
DB.quote_identifier(ident) |
Please email us if you think of any other ones!