diff --git a/framework/yii/db/oci/ColumnSchema.php b/framework/yii/db/oci/ColumnSchema.php
index 90c80fd..9436c78 100644
--- a/framework/yii/db/oci/ColumnSchema.php
+++ b/framework/yii/db/oci/ColumnSchema.php
@@ -1,88 +1,92 @@
 <?php
 namespace yii\db\oci;
 
-
-
 class ColumnSchema extends \yii\db\ColumnSchema
 {
-    
+
     /**
      * Initializes the column with its DB type and default value.
      * This sets up the column's PHP type, size, precision, scale as well as default value.
-     * @param string $dbType the column's DB type
-     * @param mixed $defaultValue the default value
+     * 
+     * @param string $dbType
+     *            the column's DB type
+     * @param mixed $defaultValue
+     *            the default value
      */
     public function extract($dbType, $defaultValue)
     {
-        $this->dbType=$dbType;
+        $this->dbType = $dbType;
         $this->extractType($dbType);
         $this->extractLimit($dbType);
-        if($defaultValue!==null)
+        if ($defaultValue !== null)
             $this->extractDefault($defaultValue);
     }
-    
+
     /**
      * Extracts the PHP type from DB type.
-     * @param string $dbType DB type
+     * 
+     * @param string $dbType
+     *            DB type
      * @return string
      */
-    protected function extractOraType($dbType){
-        if(strpos($dbType,'FLOAT')!==false) return 'double';
-    
-        if (strpos($dbType,'NUMBER')!==false || strpos($dbType,'INTEGER')!==false)
-        {
-            if(strpos($dbType,'(') && preg_match('/\((.*)\)/',$dbType,$matches))
-            {
-                $values=explode(',',$matches[1]);
-                if(isset($values[1]) and (((int)$values[1]) > 0))
+    protected function extractOraType($dbType)
+    {
+        if (strpos($dbType, 'FLOAT') !== false)
+            return 'double';
+        
+        if (strpos($dbType, 'NUMBER') !== false || strpos($dbType, 'INTEGER') !== false) {
+            if (strpos($dbType, '(') && preg_match('/\((.*)\)/', $dbType, $matches)) {
+                $values = explode(',', $matches[1]);
+                if (isset($values[1]) and (((int) $values[1]) > 0))
                     return 'double';
                 else
                     return 'integer';
-            }
-            else
+            } else
                 return 'double';
-        }
-        else
+        } else
             return 'string';
     }
-    
+
+    /**
+     * Extracts the PHP type from DB type.
+     * 
+     * @param string $dbType
+     *            DB type
+     */
+    protected function extractType($dbType)
+    {
+        $this->type = $this->extractOraType($dbType);
+    }
+
     /**
-	 * Extracts the PHP type from DB type.
-	 * @param string $dbType DB type
-	 */
-	protected function extractType($dbType)
-	{
-		$this->type=$this->extractOraType($dbType);
-	}
-    
-	/**
-	 * Extracts size, precision and scale information from column's DB type.
-	 * @param string $dbType the column's DB type
-	 */
-	protected function extractLimit($dbType)
-	{
-	    if(strpos($dbType,'(') && preg_match('/\((.*)\)/',$dbType,$matches))
-	    {
-	        $values=explode(',',$matches[1]);
-	        $this->size=$this->precision=(int)$values[0];
-	        if(isset($values[1]))
-	            $this->scale=(int)$values[1];
-	    }
-	}
-    
+     * Extracts size, precision and scale information from column's DB type.
+     * 
+     * @param string $dbType
+     *            the column's DB type
+     */
+    protected function extractLimit($dbType)
+    {
+        if (strpos($dbType, '(') && preg_match('/\((.*)\)/', $dbType, $matches)) {
+            $values = explode(',', $matches[1]);
+            $this->size = $this->precision = (int) $values[0];
+            if (isset($values[1]))
+                $this->scale = (int) $values[1];
+        }
+    }
+
     /**
-	 * Extracts the default value for the column.
-	 * The value is typecasted to correct PHP type.
-	 * @param mixed $defaultValue the default value obtained from metadata
-	 */
-	protected function extractDefault($defaultValue)
-	{
-		if(stripos($defaultValue,'timestamp')!==false) {
-			$this->defaultValue=null;
-		}
-		else {
-			$this->defaultValue=$this->typecast($defaultValue);
-		}
-	}
-    
+     * Extracts the default value for the column.
+     * The value is typecasted to correct PHP type.
+     * 
+     * @param mixed $defaultValue
+     *            the default value obtained from metadata
+     */
+    protected function extractDefault($defaultValue)
+    {
+        if (stripos($defaultValue, 'timestamp') !== false) {
+            $this->defaultValue = null;
+        } else {
+            $this->defaultValue = $this->typecast($defaultValue);
+        }
+    }
 }
diff --git a/framework/yii/db/oci/QueryBuilder.php b/framework/yii/db/oci/QueryBuilder.php
index 3ee27f1..ac3aebb 100644
--- a/framework/yii/db/oci/QueryBuilder.php
+++ b/framework/yii/db/oci/QueryBuilder.php
@@ -1,75 +1,78 @@
 <?php
-
 namespace yii\db\oci;
 
 use yii\db\Exception;
 use yii\base\InvalidParamException;
 
 /**
- * QueryBuilder is the query builder for MySQL databases.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @since 2.0
+ * QueryBuilder is the query builder for Oracle databases.
+ * 
  */
-class QueryBuilder extends \yii\db\QueryBuilder {
-	
-	private $sql;
-
-	public function build($query) {
-		//var_dump($query);exit;
-		$params = $query->params;
-		$clauses = [
-			$this->buildSelect($query->select, $query->distinct, $query->selectOption),
-			$this->buildFrom($query->from),
-			$this->buildJoin($query->join, $params),
-			$this->buildWhere($query->where, $params),
-			$this->buildGroupBy($query->groupBy),
-			$this->buildHaving($query->having, $params),
-			$this->buildUnion($query->union, $params),
-			$this->buildOrderBy($query->orderBy),
-			//$this->buildLimit($query->limit, $query->offset),
-		];
-		//var_dump( [implode($this->separator, array_filter($clauses)), $params]);exit;
-		$this->sql = implode($this->separator, array_filter($clauses));
-		
-		if (!is_null($query->limit) && !is_null($query->offset)) {
-			$this->sql = $this->buildLimit($query->limit, $query->offset);
-		}
-		return [$this->sql, $params];
-		//return [implode($this->separator, array_filter($clauses)), $params];
-	}
+class QueryBuilder extends \yii\db\QueryBuilder
+{
 
-	public function buildLimit($limit, $offset) {
-		//var_dump($limit >= 0);
-		//var_dump($offset);exit;
-		//var_dump($limit, $offset);
-		if (($limit < 0) && ($offset < 0)) {
-			return $this->sql;
-		}
-		$filters = array();
-		if ($offset > 0) {
-			$filters[] = 'rowNumId > ' . (int) $offset;
-		}
+    private $sql;
 
-		if ($limit >= 0) {
-			$filters[] = 'rownum <= ' . (int) $limit;
-		}
-
-		if (count($filters) > 0) {
-			$filter = implode(' and ', $filters);
-			$filter = " WHERE " . $filter;
-		} else {
-			$filter = '';
-		}
+    public function build($query)
+    {
+        // var_dump($query);exit;
+        $params = $query->params;
+		$clauses = [ 
+				$this->buildSelect ( $query->select, $query->distinct, $query->selectOption ),
+				$this->buildFrom ( $query->from ),
+				$this->buildJoin ( $query->join, $params ),
+				$this->buildWhere ( $query->where, $params ),
+				$this->buildGroupBy ( $query->groupBy ),
+				$this->buildHaving ( $query->having, $params ),
+				$this->buildUnion ( $query->union, $params ),
+				$this->buildOrderBy ( $query->orderBy ) 
+		// $this->buildLimit($query->limit, $query->offset),
+		
+        ;
+        // var_dump( [implode($this->separator, array_filter($clauses)), $params]);exit;
+        $this->sql = implode($this->separator, array_filter($clauses));
+        
+        if (! is_null($query->limit) && ! is_null($query->offset)) {
+            $this->sql = $this->buildLimit($query->limit, $query->offset);
+        }
+        return [
+            $this->sql,
+            $params
+        ];
+        // return [implode($this->separator, array_filter($clauses)), $params];
+    }
 
-		$sql = <<<EOD
+    public function buildLimit($limit, $offset)
+    {
+        // var_dump($limit >= 0);
+        // var_dump($offset);exit;
+        // var_dump($limit, $offset);
+        if (($limit < 0) && ($offset < 0)) {
+            return $this->sql;
+        }
+        $filters = array();
+        if ($offset > 0) {
+            $filters[] = 'rowNumId > ' . (int) $offset;
+        }
+        
+        if ($limit >= 0) {
+            $filters[] = 'rownum <= ' . (int) $limit;
+        }
+        
+        if (count($filters) > 0) {
+            $filter = implode(' and ', $filters);
+            $filter = " WHERE " . $filter;
+        } else {
+            $filter = '';
+        }
+        
+        $sql = <<<EOD
 WITH USER_SQL AS ({$this->sql}),
 	PAGINATION AS (SELECT USER_SQL.*, rownum as rowNumId FROM USER_SQL)
 SELECT *
 FROM PAGINATION
 {$filter}
 EOD;
-		return $sql;
-	}
-
+        return $sql;
+    }
 }
diff --git a/framework/yii/db/oci/Schema.php b/framework/yii/db/oci/Schema.php
index 2e247d9..2830faf 100644
--- a/framework/yii/db/oci/Schema.php
+++ b/framework/yii/db/oci/Schema.php
@@ -1,119 +1,137 @@
 <?php
-
 namespace yii\db\oci;
 
 use yii\db\TableSchema;
 use yii\db\oci\ColumnSchema;
 
-class Schema extends \yii\db\Schema {
-
-	private $_defaultSchema = '';
-
-	public function createQueryBuilder() {
-		return new QueryBuilder($this->db);
-	}
-
-	public function quoteTableName($name) {
-		if (strpos($name, '.') === false) {
-			return $this->quoteSimpleTableName($name);
-		}
-		$parts = explode('.', $name);
-		foreach ($parts as $i => $part) {
-			$parts[$i] = $this->quoteSimpleTableName($part);
-		}
-		return implode('.', $parts);
-	}
-
-	public function quoteSimpleTableName($name) {
-		return '"' . $name . '"';
-		//return $name;
-	}
-
-	public function quoteColumnName($name) {
-		if (($pos = strrpos($name, '.')) !== false) {
-			$prefix = $this->quoteTableName(substr($name, 0, $pos)) . '.';
-			$name = substr($name, $pos + 1);
-		} else {
-			$prefix = '';
-		}
-		return $prefix . ($name === '*' ? $name : $this->quoteSimpleColumnName($name));
-	}
-
-	public function quoteSimpleColumnName($name) {
-		return '"' . $name . '"';
-		//return $name;
-	}
-
-	public function loadTableSchema($name) {
-		$table = new TableSchema();
-		$this->resolveTableNames($table, $name);
-		// $this->findPrimaryKeys($table);        
-		if ($this->findColumns($table)) {
-			//$this->findForeignKeys($table);
-			$this->findConstraints($table);
-			return $table;
-		}
-	}
-
-	/**
-	 * Resolves the table name and schema name (if any).
-	 *
-	 * @param TableSchema $table the table metadata object
-	 * @param string $name the table name
-	 */
-	protected function resolveTableNames($table, $name) {
-		$parts = explode('.', str_replace('"', '', $name));
-		if (isset($parts[1])) {
-			$table->schemaName = $parts[0];
-			$table->name = $parts[1];
-		} else {
-			$table->name = $parts[0];
-		}
-
-		if ($table->schemaName === null) {
-			$table->schemaName = $this->getDefaultSchema();
-		}
-	}
-
-	/**
-	 *
-	 * @return string default schema.
-	 */
-	public function getDefaultSchema() {
-		if (!strlen($this->_defaultSchema)) {
-			$this->setDefaultSchema(strtoupper($this->db->username));
-		}
-
-		return $this->_defaultSchema;
-	}
-
-	/**
-	 *
-	 * @param string $schema default schema.
-	 */
-	public function setDefaultSchema($schema) {
-		$this->_defaultSchema = $schema;
-	}
-
-	public function getLastInsertID($sequenceName = '') {
-		if ($this->db->isActive) {
-			$sql = "select {$sequenceName}.currval from dual";
-			return $this->db->createCommand($sql)->queryScalar();
-		} else {
-			throw new InvalidCallException('DB Connection is not active.');
-		}
-	}
-
-	/**
-	 * Collects the table column metadata.
-	 * @param COciTableSchema $table the table metadata
-	 * @return boolean whether the table exists in the database
-	 */
-	protected function findColumns($table) {
-		$schemaName = $table->schemaName;
-		$tableName = $table->name;
-
-		$sql = <<<EOD
+/**
+ * Schema is the class for retrieving metadata information from an Oracle database.
+ * 
+ */
+
+class Schema extends \yii\db\Schema
+{
+
+    private $_defaultSchema = '';
+
+    public function createQueryBuilder()
+    {
+        return new QueryBuilder($this->db);
+    }
+
+    public function quoteTableName($name)
+    {
+        if (strpos($name, '.') === false) {
+            return $this->quoteSimpleTableName($name);
+        }
+        $parts = explode('.', $name);
+        foreach ($parts as $i => $part) {
+            $parts[$i] = $this->quoteSimpleTableName($part);
+        }
+        return implode('.', $parts);
+    }
+
+    public function quoteSimpleTableName($name)
+    {
+        return '"' . $name . '"';
+        // return $name;
+    }
+
+    public function quoteColumnName($name)
+    {
+        if (($pos = strrpos($name, '.')) !== false) {
+            $prefix = $this->quoteTableName(substr($name, 0, $pos)) . '.';
+            $name = substr($name, $pos + 1);
+        } else {
+            $prefix = '';
+        }
+        return $prefix . ($name === '*' ? $name : $this->quoteSimpleColumnName($name));
+    }
+
+    public function quoteSimpleColumnName($name)
+    {
+        return '"' . $name . '"';
+        // return $name;
+    }
+
+    public function loadTableSchema($name)
+    {
+        $table = new TableSchema();
+        $this->resolveTableNames($table, $name);
+        // $this->findPrimaryKeys($table);
+        if ($this->findColumns($table)) {
+            // $this->findForeignKeys($table);
+            $this->findConstraints($table);
+            return $table;
+        }
+    }
+
+    /**
+     * Resolves the table name and schema name (if any).
+     *
+     * @param TableSchema $table
+     *            the table metadata object
+     * @param string $name
+     *            the table name
+     */
+    protected function resolveTableNames($table, $name)
+    {
+        $parts = explode('.', str_replace('"', '', $name));
+        if (isset($parts[1])) {
+            $table->schemaName = $parts[0];
+            $table->name = $parts[1];
+        } else {
+            $table->name = $parts[0];
+        }
+        
+        if ($table->schemaName === null) {
+            $table->schemaName = $this->getDefaultSchema();
+        }
+    }
+
+    /**
+     *
+     * @return string default schema.
+     */
+    public function getDefaultSchema()
+    {
+        if (! strlen($this->_defaultSchema)) {
+            $this->setDefaultSchema(strtoupper($this->db->username));
+        }
+        
+        return $this->_defaultSchema;
+    }
+
+    /**
+     *
+     * @param string $schema
+     *            default schema.
+     */
+    public function setDefaultSchema($schema)
+    {
+        $this->_defaultSchema = $schema;
+    }
+
+    public function getLastInsertID($sequenceName = '')
+    {
+        if ($this->db->isActive) {
+            $sql = "select {$sequenceName}.currval from dual";
+            return $this->db->createCommand($sql)->queryScalar();
+        } else {
+            throw new InvalidCallException('DB Connection is not active.');
+        }
+    }
+
+    /**
+     * Collects the table column metadata.
+     *     
+     */
+    protected function findColumns($table)
+    {
+        $schemaName = $table->schemaName;
+        $tableName = $table->name;
+        
+        $sql = <<<EOD
 SELECT a.column_name, a.data_type ||
     case
         when data_precision is not null
@@ -142,27 +160,29 @@ WHERE
 	and b.object_name = '{$tableName}'
 ORDER by a.column_id
 EOD;
-
-
-		try {
-			$columns = $this->db->createCommand($sql)->queryAll();
-		} catch (\Exception $e) {
-			return false;
-		}
-
-		foreach ($columns as $column) {
-			$c = $this->createColumn($column);
-
-			$table->columns[$c->name] = $c;
-			if ($c->isPrimaryKey) {
-				if ($table->primaryKey === null) {
-					$table->primaryKey = $c->name;
-				} elseif (is_string($table->primaryKey)) {
-					$table->primaryKey = array($table->primaryKey, $c->name);
-				} else {
-					$table->primaryKey[] = $c->name;
-				}
-				$sql = "select sequence_name
+        
+        try {
+            $columns = $this->db->createCommand($sql)->queryAll();
+        } catch (\Exception $e) {
+            return false;
+        }
+        
+        foreach ($columns as $column) {
+            $c = $this->createColumn($column);
+            
+            $table->columns[$c->name] = $c;
+            if ($c->isPrimaryKey) {
+                if ($table->primaryKey === null) {
+                    $table->primaryKey = $c->name;
+                } elseif (is_string($table->primaryKey)) {
+                    $table->primaryKey = array(
+                        $table->primaryKey,
+                        $c->name
+                    );
+                } else {
+                    $table->primaryKey[] = $c->name;
+                }
+                $sql = "select sequence_name
 from user_tables tabs
 join user_triggers trigs
   on trigs.table_name = tabs.table_name
@@ -172,31 +192,33 @@ join user_sequences seqs
   on seqs.sequence_name = deps.referenced_name
 where tabs.table_name = '{$tableName}'
  and trigs.triggering_event = 'INSERT'";
-				try {
-					$seqName = $this->db->createCommand($sql)->queryScalar();
-				} catch (\Exception $e) {
-					return false;
-				}
-				$table->sequenceName = $seqName;
-				$c->autoIncrement = true;
-			}
-		}
-		return true;
-	}
-
-	protected function createColumn($column) {
-		$c = new ColumnSchema;
-		$c->name = $column['COLUMN_NAME'];
-		$c->allowNull = $column['NULLABLE'] === 'Y';
-		$c->isPrimaryKey = strpos($column['KEY'], 'P') !== false;
-		$c->extract($column['DATA_TYPE'], $column['DATA_DEFAULT']);
-		$c->comment = $column['COLUMN_COMMENT'] === null ? '' : $column['COLUMN_COMMENT'];
-
-		return $c;
-	}
-
-	protected function findConstraints($table) {
-		$sql = <<<EOD
+                try {
+                    $seqName = $this->db->createCommand($sql)->queryScalar();
+                } catch (\Exception $e) {
+                    return false;
+                }
+                $table->sequenceName = $seqName;
+                $c->autoIncrement = true;
+            }
+        }
+        return true;
+    }
+
+    protected function createColumn($column)
+    {
+        $c = new ColumnSchema();
+        $c->name = $column['COLUMN_NAME'];
+        $c->allowNull = $column['NULLABLE'] === 'Y';
+        $c->isPrimaryKey = strpos($column['KEY'], 'P') !== false;
+        $c->extract($column['DATA_TYPE'], $column['DATA_DEFAULT']);
+        $c->comment = $column['COLUMN_COMMENT'] === null ? '' : $column['COLUMN_COMMENT'];
+        
+        return $c;
+    }
+
+    protected function findConstraints($table)
+    {
+        $sql = <<<EOD
 		SELECT D.constraint_type as CONSTRAINT_TYPE, C.COLUMN_NAME, C.position, D.r_constraint_name,
                 E.table_name as table_ref, f.column_name as column_ref,
             	C.table_name
@@ -209,117 +231,134 @@ where tabs.table_name = '{$tableName}'
            and D.constraint_type <> 'P'
         order by d.constraint_name, c.position
 EOD;
-		$command = $this->db->createCommand($sql);
-		foreach ($command->queryAll() as $row) {
-			if ($row['CONSTRAINT_TYPE'] === 'R') {   // foreign key
-				$name = $row["COLUMN_NAME"];
-				$table->foreignKeys[$name] = array($row["TABLE_REF"], $row["COLUMN_REF"]);
-				/*
-				  if (isset($table->columns[$name])) {
-				  $table->columns[$name]->isForeignKey = true;
-				  }
-				 * 
-				 */
-			}
-		}
-	}
-
-	/**
-	 * Returns all table names in the database.
-	 * @param string $schema the schema of the tables. Defaults to empty string, meaning the current or default schema.
-	 * If not empty, the returned table names will be prefixed with the schema name.
-	 * @return array all table names in the database.
-	 */
-	protected function findTableNames($schema = '') {
-		if ($schema === '') {
-			$sql = <<<EOD
+        $command = $this->db->createCommand($sql);
+        foreach ($command->queryAll() as $row) {
+            if ($row['CONSTRAINT_TYPE'] === 'R') { // foreign key
+                $name = $row["COLUMN_NAME"];
+                $table->foreignKeys[$name] = array(
+                    $row["TABLE_REF"],
+                    $row["COLUMN_REF"]
+                );
+                /*
+                 * if (isset($table->columns[$name])) { $table->columns[$name]->isForeignKey = true; }
+                 */
+            }
+        }
+    }
+
+    /**
+     * Returns all table names in the database.
+     * 
+     * @param string $schema
+     *            the schema of the tables. Defaults to empty string, meaning the current or default schema.
+     *            If not empty, the returned table names will be prefixed with the schema name.
+     * @return array all table names in the database.
+     */
+    protected function findTableNames($schema = '')
+    {
+        if ($schema === '') {
+            $sql = <<<EOD
 SELECT table_name, '{$schema}' as table_schema FROM user_tables
 EOD;
-			$command = $this->db->createCommand($sql);
-		} else {
-			$sql = <<<EOD
+            $command = $this->db->createCommand($sql);
+        } else {
+            $sql = <<<EOD
 SELECT object_name as table_name, owner as table_schema FROM all_objects
 WHERE object_type = 'TABLE' AND owner=:schema
 EOD;
-			$command = $this->db > createCommand($sql);
-			$command->bindParam(':schema', $schema);
-		}
-
-		$rows = $command->queryAll();
-		$names = array();
-		foreach ($rows as $row) {
-			if ($schema === $this->getDefaultSchema() || $schema === '') {
-				$names[] = $row['TABLE_NAME'];
-			} else {
-				$names[] = $row['TABLE_SCHEMA'] . '.' . $row['TABLE_NAME'];
-			}
-		}
-		return $names;
-	}
-
-	/**
-	 * Builds a SQL statement for renaming a DB table.
-	 * @param string $table the table to be renamed. The name will be properly quoted by the method.
-	 * @param string $newName the new table name. The name will be properly quoted by the method.
-	 * @return string the SQL statement for renaming a DB table.
-	 * @since 1.1.6
-	 */
-	public function renameTable($table, $newName) {
-		return 'ALTER TABLE ' . $this->quoteTableName($table) . ' RENAME TO ' . $this->quoteTableName($newName);
-	}
-
-	/**
-	 * Builds a SQL statement for changing the definition of a column.
-	 * @param string $table the table whose column is to be changed. The table name will be properly quoted by the method.
-	 * @param string $column the name of the column to be changed. The name will be properly quoted by the method.
-	 * @param string $type the new column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
-	 * into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
-	 * For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
-	 * @return string the SQL statement for changing the definition of a column.
-	 * @since 1.1.6
-	 */
-	public function alterColumn($table, $column, $type) {
-		$type = $this->getColumnType($type);
-		$sql = 'ALTER TABLE ' . $this->quoteTableName($table) . ' MODIFY '
-				. $this->quoteColumnName($column) . ' '
-				. $this->getColumnType($type);
-		return $sql;
-	}
-
-	/**
-	 * Builds a SQL statement for dropping an index.
-	 * @param string $name the name of the index to be dropped. The name will be properly quoted by the method.
-	 * @param string $table the table whose index is to be dropped. The name will be properly quoted by the method.
-	 * @return string the SQL statement for dropping an index.
-	 * @since 1.1.6
-	 */
-	public function dropIndex($name, $table) {
-		return 'DROP INDEX ' . $this->quoteTableName($name);
-	}
-
-	/**
-	 * Resets the sequence value of a table's primary key.
-	 * The sequence will be reset such that the primary key of the next new row inserted
-	 * will have the specified value or 1.
-	 * @param CDbTableSchema $table the table schema whose primary key sequence will be reset
-	 * @param mixed $value the value for the primary key of the next new row inserted. If this is not set,
-	 * the next new row's primary key will have a value 1.
-	 * @since 1.1.13
-	 */
-	public function resetSequence($table, $value = 1) {
-		$seq = $table->name . "_SEQ";
-		if ($table->sequenceName !== null) {
-			$this->db->createCommand("DROP SEQUENCE " . $seq)->execute();
-
-			$createSequenceSql = <<< SQL
+            $command = $this->db > createCommand($sql);
+            $command->bindParam(':schema', $schema);
+        }
+        
+        $rows = $command->queryAll();
+        $names = array();
+        foreach ($rows as $row) {
+            if ($schema === $this->getDefaultSchema() || $schema === '') {
+                $names[] = $row['TABLE_NAME'];
+            } else {
+                $names[] = $row['TABLE_SCHEMA'] . '.' . $row['TABLE_NAME'];
+            }
+        }
+        return $names;
+    }
+
+    /**
+     * Builds a SQL statement for renaming a DB table.
+     * 
+     * @param string $table
+     *            the table to be renamed. The name will be properly quoted by the method.
+     * @param string $newName
+     *            the new table name. The name will be properly quoted by the method.
+     * @return string the SQL statement for renaming a DB table.
+     * @since 1.1.6
+     */
+    public function renameTable($table, $newName)
+    {
+        return 'ALTER TABLE ' . $this->quoteTableName($table) . ' RENAME TO ' . $this->quoteTableName($newName);
+    }
+
+    /**
+     * Builds a SQL statement for changing the definition of a column.
+     * 
+     * @param string $table
+     *            the table whose column is to be changed. The table name will be properly quoted by the method.
+     * @param string $column
+     *            the name of the column to be changed. The name will be properly quoted by the method.
+     * @param string $type
+     *            the new column type. The {@link getColumnType} method will be invoked to convert abstract column type (if any)
+     *            into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL.
+     *            For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'.
+     * @return string the SQL statement for changing the definition of a column.
+     * @since 1.1.6
+     */
+    public function alterColumn($table, $column, $type)
+    {
+        $type = $this->getColumnType($type);
+        $sql = 'ALTER TABLE ' . $this->quoteTableName($table) . ' MODIFY ' . $this->quoteColumnName($column) . ' ' . $this->getColumnType($type);
+        return $sql;
+    }
+
+    /**
+     * Builds a SQL statement for dropping an index.
+     * 
+     * @param string $name
+     *            the name of the index to be dropped. The name will be properly quoted by the method.
+     * @param string $table
+     *            the table whose index is to be dropped. The name will be properly quoted by the method.
+     * @return string the SQL statement for dropping an index.
+     * @since 1.1.6
+     */
+    public function dropIndex($name, $table)
+    {
+        return 'DROP INDEX ' . $this->quoteTableName($name);
+    }
+
+    /**
+     * Resets the sequence value of a table's primary key.
+     * The sequence will be reset such that the primary key of the next new row inserted
+     * will have the specified value or 1.
+     * 
+     * @param CDbTableSchema $table
+     *            the table schema whose primary key sequence will be reset
+     * @param mixed $value
+     *            the value for the primary key of the next new row inserted. If this is not set,
+     *            the next new row's primary key will have a value 1.
+     * @since 1.1.13
+     */
+    public function resetSequence($table, $value = 1)
+    {
+        $seq = $table->name . "_SEQ";
+        if ($table->sequenceName !== null) {
+            $this->db->createCommand("DROP SEQUENCE " . $seq)->execute();
+            
+            $createSequenceSql = <<< SQL
 create sequence $seq
 start with $value
 increment by 1
 nomaxvalue
 nocache
 SQL;
-			$this->db->createCommand($createSequenceSql)->execute();
-		}
-	}
-
+            $this->db->createCommand($createSequenceSql)->execute();
+        }
+    }
 }