...

framework/db/dao/Command.php

@@ -20,15 +20,20 @@ use yii\db\Exception;
  *
  * To execute a non-query SQL (such as INSERT, DELETE, UPDATE), call [[execute]].
  * To execute a SQL statement that returns result data set (such as SELECT),
- * use [[query]], [[queryRow]], [[queryColumn]], or [[queryScalar]].
+ * use [[queryAll]], [[queryRow]], [[queryColumn]], [[queryScalar]], or [[query]].
+ * For example,
+ *
+ * ~~~
+ * $users = \Yii::app()->db->createCommand('SELECT * FROM tbl_user')->queryAll();
+ * ~~~
  *
  * Command supports SQL statement preparation and parameter binding.
  * Call [[bindValue]] to bind a value to a SQL parameter;
  * Call [[bindParam]] to bind a PHP variable to a SQL parameter.
  * When binding a parameter, the SQL statement is automatically prepared.
- * You may also call [[prepare]] to explicitly prepare a SQL statement.
+ * You may also call [[prepare]] explicitly to prepare a SQL statement.
  *
- * Command can also be used as a query builder that builds and executes a SQL statement
+ * Command can be used as a query builder that builds and executes a SQL statement
  * from code fragments. For example,
  *
  * ~~~

framework/db/dao/DataReader.php

@@ -37,6 +37,9 @@ use yii\db\Exception;
  */
 class DataReader extends \yii\base\Object implements \Iterator, \Countable
 {
+	/**
+	 * @var \PDOStatement the PDOStatement associated with the command
+	 */
 	private $_statement;
 	private $_closed = false;
 	private $_row;
@@ -48,7 +51,7 @@ class DataReader extends \yii\base\Object implements \Iterator, \Countable
 	 */
 	public function __construct(Command $command)
 	{
-		$this->_statement = $command->getPdoStatement();
+		$this->_statement = $command->pdoStatement;
 		$this->_statement->setFetchMode(\PDO::FETCH_ASSOC);
 	}
 

framework/db/dao/Transaction.php

@@ -45,7 +45,6 @@ class Transaction extends \yii\base\Object
 	public $active;
 	/**
 	 * @var Connection the database connection that this transaction is associated with.
-	 * This property is set true when the transaction is started.
 	 */
 	public $connection;
 
@@ -70,9 +69,8 @@ class Transaction extends \yii\base\Object
 			\Yii::trace('Committing transaction', __CLASS__);
 			$this->connection->pdo->commit();
 			$this->active = false;
-		}
-		else {
-			throw new Exception('Transaction is inactive and cannot perform commit operation.');
+		} else {
+			throw new Exception('Failed to commit transaction: transaction was inactive.');
 		}
 	}
 
@@ -86,9 +84,8 @@ class Transaction extends \yii\base\Object
 			\Yii::trace('Rolling back transaction', __CLASS__);
 			$this->connection->pdo->rollBack();
 			$this->active = false;
-		}
-		else {
-			throw new Exception('Transaction is inactive and cannot perform roll back operation.');
+		} else {
+			throw new Exception('Failed to roll back transaction: transaction was inactive.');
 		}
 	}
 }