3 files changed, 13 insertions, 8 deletions
diff --git a/framework/Data/TDbCommand.php b/framework/Data/TDbCommand.php
index 3d0e367a..df34207c 100644
--- a/framework/Data/TDbCommand.php
+++ b/framework/Data/TDbCommand.php
@@ -22,6 +22,9 @@
  * (such as select), use {@link query} or its convenient versions {@link queryRow}
  * and {@link queryScalar}.
  *
+ * If an SQL statement returns results (such as a SELECT SQL), the results
+ * can be accessed via the returned {@link TDbDataReader}.
+ *
  * TDbCommand supports SQL statment preparation and parameter binding.
  * Call {@link bindParameter} to bind a PHP variable to a parameter in SQL.
  * Call {@link bindValue} to bind a value to an SQL parameter.
@@ -79,7 +82,7 @@ class TDbCommand extends TComponent
 
 	/**
 	 * @return PDOStatement the underlying PDOStatement for this command
-	 * It could be null if the statement is not created yet.
+	 * It could be null if the statement is not prepared yet.
 	 */
 	public function getPdoStatement()
 	{
@@ -99,7 +102,7 @@ class TDbCommand extends TComponent
 		{
 			try
 			{
-				$this->_statement=$this->getConnection()->getPdoInstance()->prepare($sql);
+				$this->_statement=$this->getConnection()->getPdoInstance()->prepare($this->getText());
 			}
 			catch(Exception $e)
 			{
diff --git a/framework/Data/TDbConnection.php b/framework/Data/TDbConnection.php
index cfb4fd72..9ca57a4a 100644
--- a/framework/Data/TDbConnection.php
+++ b/framework/Data/TDbConnection.php
@@ -20,7 +20,7 @@ Prado::using('System.Data.TDbCommand');
  *
  * TDbConnection works together with {@link TDbCommand}, {@link TDbDataReader}
  * and {@link TDbTransaction} to provide data access to various DBMS
- * in a common set of APIs, thanks to the {@link http://www.php.net/manual/en/ref.pdo.php PDO}
+ * in a common set of APIs. They are a thin wrapper of the {@link http://www.php.net/manual/en/ref.pdo.php PDO}
  * PHP extension.
  *
  * To establish a connection, set {@link setActive Active} to true after
@@ -53,9 +53,9 @@ Prado::using('System.Data.TDbCommand');
  *
  * To use transaction, do like the following:
  * <code>
+ * $transaction=$connection->beginTransaction();
  * try
  * {
- *    $transaction=$connection->beginTransaction();
  *    $connection->createCommand($sql1)->execute();
  *    $connection->createCommand($sql2)->execute();
  *    //.... other SQL executions
@@ -136,8 +136,8 @@ class TDbConnection extends TComponent
 		{
 			try
 			{
-				$this->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
 				$this->_pdo=new PDO($this->getConnectionString(),$this->getUsername(),$this->getPassword(),$this->_attributes);
+				$this->_pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
 				$this->_active=true;
 			}
 			catch(PDOException $e)
@@ -454,7 +454,7 @@ class TDbConnection extends TComponent
 	 */
 	public function setAttribute($name,$value)
 	{
-		if($this->getActive())
+		if($this->_pdo instanceof PDO)
 			$this->_pdo->setAttribute($name,$value);
 		else
 			$this->_attributes[$name]=$value;
diff --git a/framework/Data/TDbDataReader.php b/framework/Data/TDbDataReader.php
index 32b86c1d..ad3132b0 100644
--- a/framework/Data/TDbDataReader.php
+++ b/framework/Data/TDbDataReader.php
@@ -18,14 +18,16 @@
  * To read the current row of data, call {@link read}. The method {@link readAll}
  * returns all the rows in a single array.
  *
- * TDbDataReader implements Iterator interface and thus can be used in foreach like the following:
+ * One can also retrieve the rows of data in TDbDataReader by using foreach:
  * <code>
  * foreach($reader as $row)
  *     // $row represents a row of data
  * </code>
+ * Since TDbDataReader is a forward-only stream, you can only traverse it once.
  *
  * It is possible to use a specific mode of data fetching by setting
- * {@link setFetchMode FetchMode}. See {@link
+ * {@link setFetchMode FetchMode}. See {@link http://www.php.net/manual/en/function.pdostatement-setfetchmode.php}
+ * for more details.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @version $Id $