Extract cache from yii\db\Command to yii\db\CacheableQueryTrait and use it in yii\db\Query

framework/db/ActiveQuery.php

@@ -319,7 +319,11 @@ class ActiveQuery extends Query implements ActiveQueryInterface
             $params = $this->params;
         }
 
-        return $db->createCommand($sql, $params);
+        $command = $db->createCommand($sql, $params);
+        if ($this->hasCache()) {
+            $command->cache($this->queryCacheDuration, $this->queryCacheDependency);
+        }
+        return $command;
     }
 
     /**
@@ -337,11 +341,14 @@ class ActiveQuery extends Query implements ActiveQueryInterface
             return parent::queryScalar($selectExpression, $db);
         }
 
-        return (new Query())->select([$selectExpression])
+        $command = (new Query())->select([$selectExpression])
             ->from(['c' => "({$this->sql})"])
             ->params($this->params)
-            ->createCommand($db)
-            ->queryScalar();
+            ->createCommand($db);
+        if ($this->hasCache()) {
+            $command->cache($this->queryCacheDuration, $this->queryCacheDependency);
+        }
+        return $command->queryScalar();
     }
 
     /**

framework/db/CacheableQueryTrait.php

@@ -0,0 +1,63 @@
+<?php
+
+namespace yii\db;
+
+/**
+ * Trait CacheableQueryTrait provides methods to cache query execution result.
+ *
+ * The class that uses this trait must have the $db property:
+ * @property Connection $db
+ *
+ * @author hubeiwei <hubeiwei@hotmail.com>
+ * @author Dmytro Naumenko <d.naumenko.a@gmail.com>
+ * @since 2.0.14
+ */
+trait CacheableQueryTrait
+{
+    /**
+     * @var int the default number of seconds that query results can remain valid in cache.
+     * Use 0 to indicate that the cached data will never expire. And use a negative number to indicate
+     * query cache should not be used.
+     * @see cache()
+     */
+    public $queryCacheDuration;
+    /**
+     * @var \yii\caching\Dependency the dependency to be associated with the cached query result for this command
+     * @see cache()
+     */
+    public $queryCacheDependency;
+
+    /**
+     * Enables query cache for this command or query.
+     * @param int $duration the number of seconds that query result of this command or query can remain valid in the cache.
+     * If this is not set, the value of [[Connection::queryCacheDuration]] will be used instead.
+     * Use 0 to indicate that the cached data will never expire.
+     * @param \yii\caching\Dependency $dependency the cache dependency associated with the cached result.
+     * @return $this the command or query object itself
+     */
+    public function cache($duration = null, $dependency = null)
+    {
+        $this->queryCacheDuration = $duration !== null ? $duration : $this->db->queryCacheDuration;
+        $this->queryCacheDependency = $dependency;
+        return $this;
+    }
+
+    /**
+     * Disables query cache for this command or query.
+     * @return $this the command or query object itself
+     */
+    public function noCache()
+    {
+        $this->queryCacheDuration = -1;
+        return $this;
+    }
+
+    /**
+     * Checks, whether caching is enabled
+     * @return bool
+     */
+    public function hasCache()
+    {
+        return $this->queryCacheDuration !== null || $this->queryCacheDependency !== null;
+    }
+}

framework/db/Command.php

@@ -56,6 +56,8 @@ use yii\base\NotSupportedException;
  */
 class Command extends Component
 {
+	use CacheableQueryTrait;
+
     /**
      * @var Connection the DB connection that this command is associated with
      */
@@ -75,18 +77,6 @@ class Command extends Component
      * and is used to generate [[rawSql]]. Do not modify it directly.
      */
     public $params = [];
-    /**
-     * @var int the default number of seconds that query results can remain valid in cache.
-     * Use 0 to indicate that the cached data will never expire. And use a negative number to indicate
-     * query cache should not be used.
-     * @see cache()
-     */
-    public $queryCacheDuration;
-    /**
-     * @var \yii\caching\Dependency the dependency to be associated with the cached query result for this command
-     * @see cache()
-     */
-    public $queryCacheDependency;
 
     /**
      * @var array pending parameters to be bound to the current PDO statement.
@@ -112,31 +102,6 @@ class Command extends Component
     private $_retryHandler;
 
 
-    /**
-     * Enables query cache for this command.
-     * @param int $duration the number of seconds that query result of this command can remain valid in the cache.
-     * If this is not set, the value of [[Connection::queryCacheDuration]] will be used instead.
-     * Use 0 to indicate that the cached data will never expire.
-     * @param \yii\caching\Dependency $dependency the cache dependency associated with the cached query result.
-     * @return $this the command object itself
-     */
-    public function cache($duration = null, $dependency = null)
-    {
-        $this->queryCacheDuration = $duration === null ? $this->db->queryCacheDuration : $duration;
-        $this->queryCacheDependency = $dependency;
-        return $this;
-    }
-
-    /**
-     * Disables query cache for this command.
-     * @return $this the command object itself
-     */
-    public function noCache()
-    {
-        $this->queryCacheDuration = -1;
-        return $this;
-    }
-
     /**
      * Returns the SQL statement for this command.
      * @return string the SQL statement to be executed

framework/db/Query.php

@@ -50,6 +50,7 @@ use yii\base\InvalidParamException;
 class Query extends Component implements QueryInterface
 {
     use QueryTrait;
+    use CacheableQueryTrait;
 
     /**
      * @var array the columns being selected. For example, `['id', 'name']`.
@@ -129,7 +130,11 @@ class Query extends Component implements QueryInterface
         }
         list($sql, $params) = $db->getQueryBuilder()->build($this);
 
-        return $db->createCommand($sql, $params);
+        $command = $db->createCommand($sql, $params);
+        if ($this->hasCache()) {
+            $command->cache($this->queryCacheDuration, $this->queryCacheDependency);
+        }
+        return $command;
     }
 
     /**
@@ -449,11 +454,14 @@ class Query extends Component implements QueryInterface
             return $command->queryScalar();
         }
 
-        return (new self())
+        $command = (new self())
             ->select([$selectExpression])
             ->from(['c' => $this])
-            ->createCommand($db)
-            ->queryScalar();
+            ->createCommand($db);
+        if ($this->hasCache()) {
+            $command->cache($this->queryCacheDuration, $this->queryCacheDependency);
+        }
+        return $command->queryScalar();
     }
 
     /**