| Name |
Description |
| ActiveQuery |
ActiveQuery represents a DB query associated with an Active Record class. |
| ActiveRecord |
ActiveRecord is the base class for classes representing relational data in terms of objects. |
| BaseActiveRecord |
ActiveRecord is the base class for classes representing relational data in terms of objects. |
| BatchQueryResult |
BatchQueryResult represents a batch query from which you can retrieve data in batches. |
| ColumnSchema |
ColumnSchema class describes the metadata of a column in a database table. |
| ColumnSchemaBuilder |
ColumnSchemaBuilder helps to define database schema types using a PHP interface. |
| Command |
Command represents a SQL statement to be executed against a database. |
| Connection |
Connection represents a connection to a database via [PDO](http://www.php.net/manual/en/ref.pdo.php). |
| DataReader |
DataReader represents a forward-only stream of rows from a query result set. |
| Exception |
Exception represents an exception that is caused by some DB-related operations. |
| Migration |
Migration is the base class for representing a database migration. |
| Query |
Query represents a SELECT SQL statement in a way that is independent of DBMS. |
| QueryBuilder |
QueryBuilder builds a SELECT SQL statement based on the specification given as a [[Query]] object. |
| Schema |
Schema is the base class for concrete DBMS-specific schema classes. |
| Transaction |
Transaction represents a DB transaction. |