diff --git a/framework/caching/DbCache.php b/framework/caching/DbCache.php
index 3952852..dee8c7a 100644
--- a/framework/caching/DbCache.php
+++ b/framework/caching/DbCache.php
@@ -99,7 +99,7 @@ class DbCache extends Cache
 		$query = new Query;
 		$query->select(array('data'))
 			->from($this->cacheTable)
-			->where('id = :id AND (expire = 0 OR expire >' . time() . ')', array(':id' => $key));
+			->where('[[id]] = :id AND ([[expire]] = 0 OR [[expire]] >' . time() . ')', array(':id' => $key));
 		if ($this->db->enableQueryCache) {
 			// temporarily disable and re-enable query caching
 			$this->db->enableQueryCache = false;
@@ -125,7 +125,7 @@ class DbCache extends Cache
 		$query->select(array('id', 'data'))
 			->from($this->cacheTable)
 			->where(array('id' => $keys))
-			->andWhere('(expire = 0 OR expire > ' . time() . ')');
+			->andWhere('([[expire]] = 0 OR [[expire]] > ' . time() . ')');
 
 		if ($this->db->enableQueryCache) {
 			$this->db->enableQueryCache = false;
@@ -227,7 +227,7 @@ class DbCache extends Cache
 	{
 		if ($force || mt_rand(0, 1000000) < $this->gcProbability) {
 			$this->db->createCommand()
-				->delete($this->cacheTable, 'expire > 0 AND expire < ' . time())
+				->delete($this->cacheTable, '[[expire]] > 0 AND [[expire]] < ' . time())
 				->execute();
 		}
 	}
diff --git a/framework/db/Command.php b/framework/db/Command.php
index 2a13a89..73a8346 100644
--- a/framework/db/Command.php
+++ b/framework/db/Command.php
@@ -84,42 +84,21 @@ class Command extends \yii\base\Component
 
 	/**
 	 * Specifies the SQL statement to be executed.
-	 * Any previous execution will be terminated or cancelled.
+	 * The previous SQL execution (if any) will be cancelled, and [[params]] will be cleared as well.
 	 * @param string $sql the SQL statement to be set.
 	 * @return Command this command instance
 	 */
 	public function setSql($sql)
 	{
 		if ($sql !== $this->_sql) {
-			if ($this->db->enableAutoQuoting && $sql != '') {
-				$sql = $this->expandSql($sql);
-			}
 			$this->cancel();
-			$this->_sql = $sql;
+			$this->_sql = $this->db->quoteSql($sql);
 			$this->_params = array();
 		}
 		return $this;
 	}
 
 	/**
-	 * Expands a SQL statement by quoting table and column names and replacing table prefixes.
-	 * @param string $sql the SQL to be expanded
-	 * @return string the expanded SQL
-	 */
-	protected function expandSql($sql)
-	{
-		$db = $this->db;
-		return preg_replace_callback('/(\\{\\{(.*?)\\}\\}|\\[\\[(.*?)\\]\\])/', function($matches) use($db) {
-			if (isset($matches[3])) {
-				return $db->quoteColumnName($matches[3]);
-			} else {
-				$name = str_replace('%', $db->tablePrefix, $matches[2]);
-				return $db->quoteTableName($name);
-			}
-		}, $sql);
-	}
-
-	/**
 	 * Prepares the SQL statement to be executed.
 	 * For complex SQL statement that is to be executed multiple times,
 	 * this may improve performance.
diff --git a/framework/db/Connection.php b/framework/db/Connection.php
index 1be43eb..695034a 100644
--- a/framework/db/Connection.php
+++ b/framework/db/Connection.php
@@ -223,21 +223,10 @@ class Connection extends Component
 	 * @var string the common prefix or suffix for table names. If a table name is given
 	 * as `{{%TableName}}`, then the percentage character `%` will be replaced with this
 	 * property value. For example, `{{%post}}` becomes `{{tbl_post}}` if this property is
-	 * set as `"tbl_"`. Note that this property is only effective when [[enableAutoQuoting]]
-	 * is true.
-	 * @see enableAutoQuoting
+	 * set as `"tbl_"`.
 	 */
 	public $tablePrefix;
 	/**
-	 * @var boolean whether to enable automatic quoting of table names and column names.
-	 * Defaults to true. When this property is true, any token enclosed within double curly brackets
-	 * (e.g. `{{post}}`) in a SQL statement will be treated as a table name and will be quoted
-	 * accordingly when the SQL statement is executed; and any token enclosed within double square
-	 * brackets (e.g. `[[name]]`) will be treated as a column name and quoted accordingly.
-	 * @see tablePrefix
-	 */
-	public $enableAutoQuoting = true;
-	/**
 	 * @var array mapping between PDO driver names and [[Schema]] classes.
 	 * The keys of the array are PDO driver names while the values the corresponding
 	 * schema class name or configuration. Please refer to [[\Yii::createObject()]] for
@@ -518,6 +507,27 @@ class Connection extends Component
 	}
 
 	/**
+	 * Processes a SQL statement by quoting table and column names that are enclosed within double brackets.
+	 * Tokens enclosed within double curly brackets are treated as table names, while
+	 * tokens enclosed within double square brackets are column names. They will be quoted accordingly.
+	 * Also, the percentage character "%" in a table name will be replaced with [[tablePrefix]].
+	 * @param string $sql the SQL to be quoted
+	 * @return string the quoted SQL
+	 */
+	public function quoteSql($sql)
+	{
+		$db = $this;
+		return preg_replace_callback('/(\\{\\{([\w\-\. ]+)\\}\\}|\\[\\[([\w\-\. ]+)\\]\\])/',
+			function($matches) use($db) {
+				if (isset($matches[3])) {
+					return $db->quoteColumnName($matches[3]);
+				} else {
+					return str_replace('%', $this->tablePrefix, $db->quoteTableName($matches[2]));
+				}
+			}, $sql);
+	}
+
+	/**
 	 * Returns the name of the DB driver for the current [[dsn]].
 	 * @return string name of the DB driver
 	 */
diff --git a/framework/db/Schema.php b/framework/db/Schema.php
index 71bc9a2..d8d89bc 100644
--- a/framework/db/Schema.php
+++ b/framework/db/Schema.php
@@ -248,7 +248,7 @@ abstract class Schema extends \yii\base\Object
 	/**
 	 * Quotes a table name for use in a query.
 	 * If the table name contains schema prefix, the prefix will also be properly quoted.
-	 * If the table name is already quoted or contains special characters including '(', '[[' and '{{',
+	 * If the table name is already quoted or contains '(' or '{{',
 	 * then this method will do nothing.
 	 * @param string $name table name
 	 * @return string the properly quoted table name
@@ -256,7 +256,7 @@ abstract class Schema extends \yii\base\Object
 	 */
 	public function quoteTableName($name)
 	{
-		if (strpos($name, '(') !== false || strpos($name, '[[') !== false || strpos($name, '{{') !== false) {
+		if (strpos($name, '(') !== false || strpos($name, '{{') !== false) {
 			return $name;
 		}
 		if (strpos($name, '.') === false) {
@@ -273,7 +273,7 @@ abstract class Schema extends \yii\base\Object
 	/**
 	 * Quotes a column name for use in a query.
 	 * If the column name contains prefix, the prefix will also be properly quoted.
-	 * If the column name is already quoted or contains special characters including '(', '[[' and '{{',
+	 * If the column name is already quoted or contains '(', '[[' or '{{',
 	 * then this method will do nothing.
 	 * @param string $name column name
 	 * @return string the properly quoted column name
@@ -320,13 +320,13 @@ abstract class Schema extends \yii\base\Object
 	/**
 	 * Returns the real name of a table name.
 	 * This method will strip off curly brackets from the given table name
-	 * and replace the percentage character in the name with [[Connection::tablePrefix]].
+	 * and replace the percentage character '%' with [[Connection::tablePrefix]].
 	 * @param string $name the table name to be converted
 	 * @return string the real name of the given table name
 	 */
 	public function getRealTableName($name)
 	{
-		if ($this->db->enableAutoQuoting && strpos($name, '{{') !== false) {
+		if (strpos($name, '{{') !== false) {
 			$name = preg_replace('/\\{\\{(.*?)\\}\\}/', '\1', $name);
 			return str_replace('%', $this->db->tablePrefix, $name);
 		} else {
diff --git a/framework/logging/DbTarget.php b/framework/logging/DbTarget.php
index e4e30ce..ce9d843 100644
--- a/framework/logging/DbTarget.php
+++ b/framework/logging/DbTarget.php
@@ -78,7 +78,8 @@ class DbTarget extends Target
 	public function export($messages)
 	{
 		$tableName = $this->db->quoteTableName($this->logTable);
-		$sql = "INSERT INTO $tableName (level, category, log_time, message) VALUES (:level, :category, :log_time, :message)";
+		$sql = "INSERT INTO $tableName ([[level]], [[category]], [[log_time]], [[message]])
+				VALUES (:level, :category, :log_time, :message)";
 		$command = $this->db->createCommand($sql);
 		foreach ($messages as $message) {
 			$command->bindValues(array(
diff --git a/framework/web/DbSession.php b/framework/web/DbSession.php
index d3afc76..2910b40 100644
--- a/framework/web/DbSession.php
+++ b/framework/web/DbSession.php
@@ -144,7 +144,7 @@ class DbSession extends Session
 		$query = new Query;
 		$data = $query->select(array('data'))
 			->from($this->sessionTable)
-			->where('expire>:expire AND id=:id', array(':expire' => time(), ':id' => $id))
+			->where('[[expire]]>:expire AND [[id]]=:id', array(':expire' => time(), ':id' => $id))
 			->createCommand($this->db)
 			->queryScalar();
 		return $data === false ? '' : $data;
@@ -214,7 +214,7 @@ class DbSession extends Session
 	public function gcSession($maxLifetime)
 	{
 		$this->db->createCommand()
-			->delete($this->sessionTable, 'expire<:expire', array(':expire' => time()))
+			->delete($this->sessionTable, '[[expire]]<:expire', array(':expire' => time()))
 			->execute();
 		return true;
 	}
diff --git a/tests/unit/framework/db/ConnectionTest.php b/tests/unit/framework/db/ConnectionTest.php
index afb4f20..256c5a9 100644
--- a/tests/unit/framework/db/ConnectionTest.php
+++ b/tests/unit/framework/db/ConnectionTest.php
@@ -59,7 +59,6 @@ class ConnectionTest extends \yiiunit\MysqlTestCase
 		$this->assertEquals('`table`', $connection->quoteTableName('`table`'));
 		$this->assertEquals('`schema`.`table`', $connection->quoteTableName('schema.table'));
 		$this->assertEquals('`schema`.`table`', $connection->quoteTableName('schema.`table`'));
-		$this->assertEquals('[[table]]', $connection->quoteTableName('[[table]]'));
 		$this->assertEquals('{{table}}', $connection->quoteTableName('{{table}}'));
 		$this->assertEquals('(table)', $connection->quoteTableName('(table)'));
 	}