diff --git a/framework/BaseYii.php b/framework/BaseYii.php
index bfe0240b77..e87e497767 100644
--- a/framework/BaseYii.php
+++ b/framework/BaseYii.php
@@ -349,7 +349,7 @@ class BaseYii
     }
 
     private static $_logger;
-    
+
     /**
      * @return Logger message logger
      */
diff --git a/framework/base/ArrayAccessTrait.php b/framework/base/ArrayAccessTrait.php
index 3d279daf9f..df1ab603fd 100644
--- a/framework/base/ArrayAccessTrait.php
+++ b/framework/base/ArrayAccessTrait.php
@@ -13,10 +13,10 @@ namespace yii\base;
  * Note that ArrayAccessTrait requires the class using it contain a property named `data` which should be an array.
  * The data will be exposed by ArrayAccessTrait to support accessing the class object like an array.
  *
+ * @property array $data
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
- *
- * @property array $data
  */
 trait ArrayAccessTrait
 {
diff --git a/framework/base/Formatter.php b/framework/base/Formatter.php
index 113ba205fe..34829d0f9f 100644
--- a/framework/base/Formatter.php
+++ b/framework/base/Formatter.php
@@ -350,6 +350,7 @@ class Formatter extends Component
         if (is_string($value)) {
             return is_numeric($value) || $value === '' ? (int) $value : strtotime($value);
         } elseif ($value instanceof DateTime || $value instanceof \DateTimeInterface) {
+            /** @var $value \DateTimeInterface */
             return $value->getTimestamp();
         } else {
             return (int) $value;
diff --git a/framework/console/controllers/FixtureController.php b/framework/console/controllers/FixtureController.php
index 5b298abdb9..d798268e8a 100644
--- a/framework/console/controllers/FixtureController.php
+++ b/framework/console/controllers/FixtureController.php
@@ -118,6 +118,7 @@ class FixtureController extends Controller
      * whitespace between names.
      * @param array|string $fixtures
      * @param array|string $except
+     * @throws \yii\console\Exception in case no fixtures are found.
      */
     public function actionUnload(array $fixtures, array $except = [])
     {
diff --git a/framework/db/ActiveRelationTrait.php b/framework/db/ActiveRelationTrait.php
index 863f6a3e60..91112de66e 100644
--- a/framework/db/ActiveRelationTrait.php
+++ b/framework/db/ActiveRelationTrait.php
@@ -257,7 +257,6 @@ trait ActiveRelationTrait
      * @param ActiveRecordInterface[] $models models
      * @param string $primaryName the primary relation name
      * @param string $name the relation name
-     * @return null
      */
     private function populateInverseRelation(&$primaryModels, $models, $primaryName, $name)
     {
@@ -368,6 +367,10 @@ trait ActiveRelationTrait
         return $buckets;
     }
 
+    /**
+     * @param array $attributes the attributes to prefix
+     * @return array
+     */
     private function prefixKeyColumns($attributes)
     {
         if ($this instanceof ActiveQuery && (!empty($this->join) || !empty($this->joinWith))) {
@@ -385,7 +388,7 @@ trait ActiveRelationTrait
             }
             if (isset($alias)) {
                 foreach ($attributes as $i => $attribute) {
-                	$attributes[$i] = "$alias.$attribute";
+                    $attributes[$i] = "$alias.$attribute";
                 }
             }
         }
diff --git a/framework/db/BaseActiveRecord.php b/framework/db/BaseActiveRecord.php
index d821e7dbc9..55b7b40fd6 100644
--- a/framework/db/BaseActiveRecord.php
+++ b/framework/db/BaseActiveRecord.php
@@ -911,7 +911,7 @@ abstract class BaseActiveRecord extends Model implements ActiveRecordInterface
      */
     public function refresh()
     {
-        /** @var ActiveQuery $record */
+        /** @var BaseActiveRecord $record */
         $record = $this->findOne($this->getPrimaryKey(true));
         if ($record === null) {
             return false;
diff --git a/framework/db/Query.php b/framework/db/Query.php
index 69afb6d828..5291c270a8 100644
--- a/framework/db/Query.php
+++ b/framework/db/Query.php
@@ -107,6 +107,7 @@ class Query extends Component implements QueryInterface
      */
     public $params = [];
 
+
     /**
      * Creates a DB command that can be used to execute this query.
      * @param Connection $db the database connection used to generate the SQL statement.
@@ -201,7 +202,6 @@ class Query extends Component implements QueryInterface
     public function all($db = null)
     {
         $rows = $this->createCommand($db)->queryAll();
-
         return $this->prepareResult($rows);
     }
 
@@ -226,7 +226,6 @@ class Query extends Component implements QueryInterface
             }
             $result[$key] = $row;
         }
-
         return $result;
     }
 
@@ -343,7 +342,6 @@ class Query extends Component implements QueryInterface
         $this->select = [new Expression('1')];
         $command = $this->createCommand($db);
         $this->select = $select;
-
         return $command->queryScalar() !== false;
     }
 
@@ -404,7 +402,6 @@ class Query extends Component implements QueryInterface
         }
         $this->select = $columns;
         $this->selectOption = $option;
-
         return $this;
     }
 
@@ -424,7 +421,6 @@ class Query extends Component implements QueryInterface
         } else {
             $this->select = array_merge($this->select, $columns);
         }
-        
         return $this;
     }
 
@@ -436,7 +432,6 @@ class Query extends Component implements QueryInterface
     public function distinct($value = true)
     {
         $this->distinct = $value;
-
         return $this;
     }
 
@@ -462,7 +457,6 @@ class Query extends Component implements QueryInterface
             $tables = preg_split('/\s*,\s*/', trim($tables), -1, PREG_SPLIT_NO_EMPTY);
         }
         $this->from = $tables;
-
         return $this;
     }
 
@@ -570,7 +564,6 @@ class Query extends Component implements QueryInterface
             $this->where = ['and', $this->where, $condition];
         }
         $this->addParams($params);
-
         return $this;
     }
 
@@ -618,7 +611,6 @@ class Query extends Component implements QueryInterface
     public function join($type, $table, $on = '', $params = [])
     {
         $this->join[] = [$type, $table, $on];
-
         return $this->addParams($params);
     }
 
@@ -643,7 +635,6 @@ class Query extends Component implements QueryInterface
     public function innerJoin($table, $on = '', $params = [])
     {
         $this->join[] = ['INNER JOIN', $table, $on];
-
         return $this->addParams($params);
     }
 
@@ -668,7 +659,6 @@ class Query extends Component implements QueryInterface
     public function leftJoin($table, $on = '', $params = [])
     {
         $this->join[] = ['LEFT JOIN', $table, $on];
-
         return $this->addParams($params);
     }
 
@@ -693,7 +683,6 @@ class Query extends Component implements QueryInterface
     public function rightJoin($table, $on = '', $params = [])
     {
         $this->join[] = ['RIGHT JOIN', $table, $on];
-
         return $this->addParams($params);
     }
 
@@ -712,7 +701,6 @@ class Query extends Component implements QueryInterface
             $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY);
         }
         $this->groupBy = $columns;
-
         return $this;
     }
 
@@ -735,7 +723,6 @@ class Query extends Component implements QueryInterface
         } else {
             $this->groupBy = array_merge($this->groupBy, $columns);
         }
-
         return $this;
     }
 
@@ -752,7 +739,6 @@ class Query extends Component implements QueryInterface
     {
         $this->having = $condition;
         $this->addParams($params);
-
         return $this;
     }
 
@@ -774,7 +760,6 @@ class Query extends Component implements QueryInterface
             $this->having = ['and', $this->having, $condition];
         }
         $this->addParams($params);
-
         return $this;
     }
 
@@ -796,7 +781,6 @@ class Query extends Component implements QueryInterface
             $this->having = ['or', $this->having, $condition];
         }
         $this->addParams($params);
-
         return $this;
     }
 
@@ -809,7 +793,6 @@ class Query extends Component implements QueryInterface
     public function union($sql, $all = false)
     {
         $this->union[] = [ 'query' => $sql, 'all' => $all ];
-
         return $this;
     }
 
@@ -823,7 +806,6 @@ class Query extends Component implements QueryInterface
     public function params($params)
     {
         $this->params = $params;
-
         return $this;
     }
 
@@ -849,7 +831,6 @@ class Query extends Component implements QueryInterface
                 }
             }
         }
-
         return $this;
     }
 }
diff --git a/framework/db/oci/QueryBuilder.php b/framework/db/oci/QueryBuilder.php
index 528d377e77..a33ad5dc2e 100644
--- a/framework/db/oci/QueryBuilder.php
+++ b/framework/db/oci/QueryBuilder.php
@@ -17,7 +17,7 @@ use yii\base\InvalidParamException;
  */
 class QueryBuilder extends \yii\db\QueryBuilder
 {
-    private $sql;
+    private $_sql;
 
     /**
      * @inheritdoc
@@ -37,16 +37,16 @@ class QueryBuilder extends \yii\db\QueryBuilder
             $this->buildHaving($query->having, $params),
             $this->buildOrderBy($query->orderBy),
         ];
-        $this->sql = implode($this->separator, array_filter($clauses));
+        $this->_sql = implode($this->separator, array_filter($clauses));
 
-        $this->sql = $this->buildLimit($query->limit, $query->offset);
+        $this->_sql = $this->buildLimit($query->limit, $query->offset);
 
         $union = $this->buildUnion($query->union, $params);
         if ($union !== '') {
-            $this->sql = "{$this->sql}{$this->separator}$union";
+            $this->_sql = "{$this->_sql}{$this->separator}$union";
         }
 
-        return [$this->sql, $params];
+        return [$this->_sql, $params];
     }
 
     public function buildLimit($limit, $offset)
@@ -64,14 +64,14 @@ class QueryBuilder extends \yii\db\QueryBuilder
             $filter = implode(' and ', $filters);
 
             return <<<EOD
-WITH USER_SQL AS ({$this->sql}),
+WITH USER_SQL AS ({$this->_sql}),
     PAGINATION AS (SELECT USER_SQL.*, rownum as rowNumId FROM USER_SQL)
 SELECT *
 FROM PAGINATION
 WHERE $filter
 EOD;
         } else {
-            return $this->sql;
+            return $this->_sql;
         }
     }
 
diff --git a/framework/web/Request.php b/framework/web/Request.php
index a194054c23..535b78049d 100644
--- a/framework/web/Request.php
+++ b/framework/web/Request.php
@@ -671,15 +671,16 @@ class Request extends \yii\base\Request
         // try to encode in UTF8 if not so
         // http://w3.org/International/questions/qa-forms-utf-8.html
         if (!preg_match('%^(?:
-                [\x09\x0A\x0D\x20-\x7E]              # ASCII
-                | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
-                | \xE0[\xA0-\xBF][\x80-\xBF]         # excluding overlongs
-                | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
-                | \xED[\x80-\x9F][\x80-\xBF]         # excluding surrogates
-                | \xF0[\x90-\xBF][\x80-\xBF]{2}      # planes 1-3
-                | [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
-                | \xF4[\x80-\x8F][\x80-\xBF]{2}      # plane 16
-                )*$%xs', $pathInfo)) {
+            [\x09\x0A\x0D\x20-\x7E]              # ASCII
+            | [\xC2-\xDF][\x80-\xBF]             # non-overlong 2-byte
+            | \xE0[\xA0-\xBF][\x80-\xBF]         # excluding overlongs
+            | [\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}  # straight 3-byte
+            | \xED[\x80-\x9F][\x80-\xBF]         # excluding surrogates
+            | \xF0[\x90-\xBF][\x80-\xBF]{2}      # planes 1-3
+            | [\xF1-\xF3][\x80-\xBF]{3}          # planes 4-15
+            | \xF4[\x80-\x8F][\x80-\xBF]{2}      # plane 16
+            )*$%xs', $pathInfo)
+        ) {
             $pathInfo = utf8_encode($pathInfo);
         }