Merge pull request #1097 from yiisoft/db-traits

docs/guide/query-builder.md

@@ -167,8 +167,8 @@ For ordering results `orderBy` and `addOrderBy` could be used:
 
 ```php
 $query->orderBy([
-	'id' => Query::SORT_ASC,
-	'name' => Query::SORT_DESC,
+	'id' => SORT_ASC,
+	'name' => SORT_DESC,
 ]);
 ```
 

framework/yii/ar/ActiveQueryInterface.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\ar;
+use yii\db\QueryInterface;
+
+/**
+ * ActiveQueryInterface defines the common interface to be implemented by active record query classes.
+ *
+ * A class implementing this interface should also use [[ActiveQueryTrait]].
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+interface ActiveQueryInterface extends QueryInterface
+{
+	/**
+	 * Sets the [[asArray]] property.
+	 * @param boolean $value whether to return the query results in terms of arrays instead of Active Records.
+	 * @return static the query object itself
+	 */
+	public function asArray($value = true);
+
+	/**
+	 * Sets the [[indexBy]] property.
+	 * @param string|callable $column the name of the column by which the query results should be indexed by.
+	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
+	 * row or model data. The signature of the callable should be:
+	 *
+	 * ~~~
+	 * // $model is an AR instance when `asArray` is false,
+	 * // or an array of column values when `asArray` is true.
+	 * function ($model)
+	 * {
+	 *     // return the index value corresponding to $model
+	 * }
+	 * ~~~
+	 *
+	 * @return static the query object itself
+	 */
+	public function indexBy($column);
+
+	/**
+	 * Specifies the relations with which this query should be performed.
+	 *
+	 * The parameters to this method can be either one or multiple strings, or a single array
+	 * of relation names and the optional callbacks to customize the relations.
+	 *
+	 * A relation name can refer to a relation defined in [[modelClass]]
+	 * or a sub-relation that stands for a relation of a related record.
+	 * For example, `orders.address` means the `address` relation defined
+	 * in the model class corresponding to the `orders` relation.
+	 *
+	 * The followings are some usage examples:
+	 *
+	 * ~~~
+	 * // find customers together with their orders and country
+	 * Customer::find()->with('orders', 'country')->all();
+	 * // find customers together with their orders and the orders' shipping address
+	 * Customer::find()->with('orders.address')->all();
+	 * // find customers together with their country and orders of status 1
+	 * Customer::find()->with([
+	 *     'orders' => function($query) {
+	 *         $query->andWhere('status = 1');
+	 *     },
+	 *     'country',
+	 * ])->all();
+	 * ~~~
+	 *
+	 * @return static the query object itself
+	 */
+	public function with();
+}

framework/yii/ar/ActiveQueryTrait.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\ar;
+
+use yii\db\ActiveRecord;
+
+/**
+ * ActiveQueryTrait implements the common methods and properties for active record query classes.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+trait ActiveQueryTrait
+{
+	/**
+	 * @var string the name of the ActiveRecord class.
+	 */
+	public $modelClass;
+	/**
+	 * @var array list of relations that this query should be performed with
+	 */
+	public $with;
+	/**
+	 * @var boolean whether to return each record as an array. If false (default), an object
+	 * of [[modelClass]] will be created to represent each record.
+	 */
+	public $asArray;
+
+
+	/**
+	 * PHP magic method.
+	 * This method allows calling static method defined in [[modelClass]] via this query object.
+	 * It is mainly implemented for supporting the feature of scope.
+	 * @param string $name the method name to be called
+	 * @param array $params the parameters passed to the method
+	 * @return mixed the method return result
+	 */
+	public function __call($name, $params)
+	{
+		if (method_exists($this->modelClass, $name)) {
+			array_unshift($params, $this);
+			call_user_func_array([$this->modelClass, $name], $params);
+			return $this;
+		} else {
+			return parent::__call($name, $params);
+		}
+	}
+
+	/**
+	 * Sets the [[asArray]] property.
+	 * @param boolean $value whether to return the query results in terms of arrays instead of Active Records.
+	 * @return static the query object itself
+	 */
+	public function asArray($value = true)
+	{
+		$this->asArray = $value;
+		return $this;
+	}
+
+	/**
+	 * Specifies the relations with which this query should be performed.
+	 *
+	 * The parameters to this method can be either one or multiple strings, or a single array
+	 * of relation names and the optional callbacks to customize the relations.
+	 *
+	 * A relation name can refer to a relation defined in [[modelClass]]
+	 * or a sub-relation that stands for a relation of a related record.
+	 * For example, `orders.address` means the `address` relation defined
+	 * in the model class corresponding to the `orders` relation.
+	 *
+	 * The followings are some usage examples:
+	 *
+	 * ~~~
+	 * // find customers together with their orders and country
+	 * Customer::find()->with('orders', 'country')->all();
+	 * // find customers together with their orders and the orders' shipping address
+	 * Customer::find()->with('orders.address')->all();
+	 * // find customers together with their country and orders of status 1
+	 * Customer::find()->with([
+	 *     'orders' => function($query) {
+	 *         $query->andWhere('status = 1');
+	 *     },
+	 *     'country',
+	 * ])->all();
+	 * ~~~
+	 *
+	 * @return static the query object itself
+	 */
+	public function with()
+	{
+		$this->with = func_get_args();
+		if (isset($this->with[0]) && is_array($this->with[0])) {
+			// the parameter is given as an array
+			$this->with = $this->with[0];
+		}
+		return $this;
+	}
+
+	/**
+	 * Converts found rows into model instances
+	 * @param array $rows
+	 * @return array|ActiveRecord[]
+	 */
+	private function createModels($rows)
+	{
+		$models = [];
+		if ($this->asArray) {
+			if ($this->indexBy === null) {
+				return $rows;
+			}
+			foreach ($rows as $row) {
+				if (is_string($this->indexBy)) {
+					$key = $row[$this->indexBy];
+				} else {
+					$key = call_user_func($this->indexBy, $row);
+				}
+				$models[$key] = $row;
+			}
+		} else {
+			/** @var ActiveRecord $class */
+			$class = $this->modelClass;
+			if ($this->indexBy === null) {
+				foreach ($rows as $row) {
+					$models[] = $class::create($row);
+				}
+			} else {
+				foreach ($rows as $row) {
+					$model = $class::create($row);
+					if (is_string($this->indexBy)) {
+						$key = $model->{$this->indexBy};
+					} else {
+						$key = call_user_func($this->indexBy, $model);
+					}
+					$models[$key] = $model;
+				}
+			}
+		}
+		return $models;
+	}
+
+	/**
+	 * @param ActiveRecord[] $models
+	 * @param array $with
+	 */
+	private function populateRelations(&$models, $with)
+	{
+		$primaryModel = new $this->modelClass;
+		$relations = $this->normalizeRelations($primaryModel, $with);
+		foreach ($relations as $name => $relation) {
+			if ($relation->asArray === null) {
+				// inherit asArray from primary query
+				$relation->asArray = $this->asArray;
+			}
+			$relation->findWith($name, $models);
+		}
+	}
+
+	/**
+	 * @param ActiveRecord $model
+	 * @param array $with
+	 * @return ActiveRelationInterface[]
+	 */
+	private function normalizeRelations($model, $with)
+	{
+		$relations = [];
+		foreach ($with as $name => $callback) {
+			if (is_integer($name)) {
+				$name = $callback;
+				$callback = null;
+			}
+			if (($pos = strpos($name, '.')) !== false) {
+				// with sub-relations
+				$childName = substr($name, $pos + 1);
+				$name = substr($name, 0, $pos);
+			} else {
+				$childName = null;
+			}
+
+			if (!isset($relations[$name])) {
+				$relation = $model->getRelation($name);
+				$relation->primaryModel = null;
+				$relations[$name] = $relation;
+			} else {
+				$relation = $relations[$name];
+			}
+
+			if (isset($childName)) {
+				$relation->with[$childName] = $callback;
+			} elseif ($callback !== null) {
+				call_user_func($callback, $relation);
+			}
+		}
+		return $relations;
+	}
+}

framework/yii/ar/ActiveRelationInterface.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\ar;
+
+/**
+ * ActiveRelationInterface defines the common interface to be implemented by active record relation classes.
+ *
+ * A class implementing this interface should also use [[ActiveRelationTrait]].
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+interface ActiveRelationInterface extends ActiveQueryInterface
+{
+	/**
+	 * Specifies the relation associated with the pivot table.
+	 * @param string $relationName the relation name. This refers to a relation declared in [[primaryModel]].
+	 * @param callable $callable a PHP callback for customizing the relation associated with the pivot table.
+	 * Its signature should be `function($query)`, where `$query` is the query to be customized.
+	 * @return static the relation object itself.
+	 */
+	public function via($relationName, $callable = null);
+}

framework/yii/ar/ActiveRelationTrait.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\ar;
+
+use yii\base\InvalidConfigException;
+use yii\db\ActiveRecord;
+
+/**
+ * ActiveRelationTrait implements the common methods and properties for active record relation classes.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+trait ActiveRelationTrait
+{
+	/**
+	 * @var boolean whether this relation should populate all query results into AR instances.
+	 * If false, only the first row of the results will be retrieved.
+	 */
+	public $multiple;
+	/**
+	 * @var ActiveRecord the primary model that this relation is associated with.
+	 * This is used only in lazy loading with dynamic query options.
+	 */
+	public $primaryModel;
+	/**
+	 * @var array the columns of the primary and foreign tables that establish the relation.
+	 * The array keys must be columns of the table for this relation, and the array values
+	 * must be the corresponding columns from the primary table.
+	 * Do not prefix or quote the column names as this will be done automatically by Yii.
+	 */
+	public $link;
+	/**
+	 * @var array the query associated with the pivot table. Please call [[via()]]
+	 * to set this property instead of directly setting it.
+	 */
+	public $via;
+
+	/**
+	 * Clones internal objects.
+	 */
+	public function __clone()
+	{
+		// make a clone of "via" object so that the same query object can be reused multiple times
+		if (is_object($this->via)) {
+			$this->via = clone $this->via;
+		} elseif (is_array($this->via)) {
+			$this->via = [$this->via[0], clone $this->via[1]];
+		}
+	}
+
+	/**
+	 * Specifies the relation associated with the pivot table.
+	 * @param string $relationName the relation name. This refers to a relation declared in [[primaryModel]].
+	 * @param callable $callable a PHP callback for customizing the relation associated with the pivot table.
+	 * Its signature should be `function($query)`, where `$query` is the query to be customized.
+	 * @return static the relation object itself.
+	 */
+	public function via($relationName, $callable = null)
+	{
+		$relation = $this->primaryModel->getRelation($relationName);
+		$this->via = [$relationName, $relation];
+		if ($callable !== null) {
+			call_user_func($callable, $relation);
+		}
+		return $this;
+	}
+
+	/**
+	 * Finds the related records and populates them into the primary models.
+	 * This method is internally used by [[ActiveQuery]]. Do not call it directly.
+	 * @param string $name the relation name
+	 * @param array $primaryModels primary models
+	 * @return array the related models
+	 * @throws InvalidConfigException
+	 */
+	public function findWith($name, &$primaryModels)
+	{
+		if (!is_array($this->link)) {
+			throw new InvalidConfigException('Invalid link: it must be an array of key-value pairs.');
+		}
+
+		if ($this->via instanceof self) {
+			// via pivot table
+			/** @var ActiveRelationTrait $viaQuery */
+			$viaQuery = $this->via;
+			$viaModels = $viaQuery->findPivotRows($primaryModels);
+			$this->filterByModels($viaModels);
+		} elseif (is_array($this->via)) {
+			// via relation
+			/** @var ActiveRelationTrait $viaQuery */
+			list($viaName, $viaQuery) = $this->via;
+			$viaQuery->primaryModel = null;
+			$viaModels = $viaQuery->findWith($viaName, $primaryModels);
+			$this->filterByModels($viaModels);
+		} else {
+			$this->filterByModels($primaryModels);
+		}
+
+		if (count($primaryModels) === 1 && !$this->multiple) {
+			$model = $this->one();
+			foreach ($primaryModels as $i => $primaryModel) {
+				if ($primaryModel instanceof ActiveRecord) {
+					$primaryModel->populateRelation($name, $model);
+				} else {
+					$primaryModels[$i][$name] = $model;
+				}
+			}
+			return [$model];
+		} else {
+			$models = $this->all();
+			if (isset($viaModels, $viaQuery)) {
+				$buckets = $this->buildBuckets($models, $this->link, $viaModels, $viaQuery->link);
+			} else {
+				$buckets = $this->buildBuckets($models, $this->link);
+			}
+
+			$link = array_values(isset($viaQuery) ? $viaQuery->link : $this->link);
+			foreach ($primaryModels as $i => $primaryModel) {
+				$key = $this->getModelKey($primaryModel, $link);
+				$value = isset($buckets[$key]) ? $buckets[$key] : ($this->multiple ? [] : null);
+				if ($primaryModel instanceof ActiveRecord) {
+					$primaryModel->populateRelation($name, $value);
+				} else {
+					$primaryModels[$i][$name] = $value;
+				}
+			}
+			return $models;
+		}
+	}
+
+	/**
+	 * @param array $models
+	 * @param array $link
+	 * @param array $viaModels
+	 * @param array $viaLink
+	 * @return array
+	 */
+	private function buildBuckets($models, $link, $viaModels = null, $viaLink = null)
+	{
+		$buckets = [];
+		$linkKeys = array_keys($link);
+		foreach ($models as $i => $model) {
+			$key = $this->getModelKey($model, $linkKeys);
+			if ($this->indexBy !== null) {
+				$buckets[$key][$i] = $model;
+			} else {
+				$buckets[$key][] = $model;
+			}
+		}
+
+		if ($viaModels !== null) {
+			$viaBuckets = [];
+			$viaLinkKeys = array_keys($viaLink);
+			$linkValues = array_values($link);
+			foreach ($viaModels as $viaModel) {
+				$key1 = $this->getModelKey($viaModel, $viaLinkKeys);
+				$key2 = $this->getModelKey($viaModel, $linkValues);
+				if (isset($buckets[$key2])) {
+					foreach ($buckets[$key2] as $i => $bucket) {
+						if ($this->indexBy !== null) {
+							$viaBuckets[$key1][$i] = $bucket;
+						} else {
+							$viaBuckets[$key1][] = $bucket;
+						}
+					}
+				}
+			}
+			$buckets = $viaBuckets;
+		}
+
+		if (!$this->multiple) {
+			foreach ($buckets as $i => $bucket) {
+				$buckets[$i] = reset($bucket);
+			}
+		}
+		return $buckets;
+	}
+
+	/**
+	 * @param ActiveRecord|array $model
+	 * @param array $attributes
+	 * @return string
+	 */
+	private function getModelKey($model, $attributes)
+	{
+		if (count($attributes) > 1) {
+			$key = [];
+			foreach ($attributes as $attribute) {
+				$key[] = $model[$attribute];
+			}
+			return serialize($key);
+		} else {
+			$attribute = reset($attributes);
+			return $model[$attribute];
+		}
+	}
+
+	/**
+	 * @param array $models
+	 */
+	private function filterByModels($models)
+	{
+		$attributes = array_keys($this->link);
+		$values = [];
+		if (count($attributes) === 1) {
+			// single key
+			$attribute = reset($this->link);
+			foreach ($models as $model) {
+				if (($value = $model[$attribute]) !== null) {
+					$values[] = $value;
+				}
+			}
+		} else {
+			// composite keys
+			foreach ($models as $model) {
+				$v = [];
+				foreach ($this->link as $attribute => $link) {
+					$v[$attribute] = $model[$link];
+				}
+				$values[] = $v;
+			}
+		}
+		$this->andWhere(['in', $attributes, array_unique($values, SORT_REGULAR)]);
+	}
+
+	/**
+	 * @param ActiveRecord[] $primaryModels
+	 * @return array
+	 */
+	private function findPivotRows($primaryModels)
+	{
+		if (empty($primaryModels)) {
+			return [];
+		}
+		$this->filterByModels($primaryModels);
+		/** @var ActiveRecord $primaryModel */
+		$primaryModel = reset($primaryModels);
+		return $this->asArray()->all($primaryModel->getDb());
+	}
+}

framework/yii/data/ActiveDataProvider.php

@@ -8,11 +8,11 @@
 namespace yii\data;
 
 use Yii;
+use yii\ar\ActiveQueryInterface;
 use yii\base\InvalidConfigException;
 use yii\base\Model;
-use yii\db\Query;
-use yii\db\ActiveQuery;
 use yii\db\Connection;
+use yii\db\QueryInterface;
 
 /**
  * ActiveDataProvider implements a data provider based on [[Query]] and [[ActiveQuery]].
@@ -54,7 +54,7 @@ use yii\db\Connection;
 class ActiveDataProvider extends BaseDataProvider
 {
 	/**
-	 * @var Query the query that is used to fetch data models and [[totalCount]]
+	 * @var QueryInterface the query that is used to fetch data models and [[totalCount]]
 	 * if it is not explicitly set.
 	 */
 	public $query;
@@ -97,8 +97,8 @@ class ActiveDataProvider extends BaseDataProvider
 	 */
 	protected function prepareModels()
 	{
-		if (!$this->query instanceof Query) {
-			throw new InvalidConfigException('The "query" property must be an instance of Query or its subclass.');
+		if (!$this->query instanceof QueryInterface) {
+			throw new InvalidConfigException('The "query" property must be an instance of a class that implements the QueryInterface e.g. yii\db\Query or its subclasses.');
 		}
 		if (($pagination = $this->getPagination()) !== false) {
 			$pagination->totalCount = $this->getTotalCount();
@@ -125,7 +125,7 @@ class ActiveDataProvider extends BaseDataProvider
 				}
 			}
 			return $keys;
-		} elseif ($this->query instanceof ActiveQuery) {
+		} elseif ($this->query instanceof ActiveQueryInterface) {
 			/** @var \yii\db\ActiveRecord $class */
 			$class = $this->query->modelClass;
 			$pks = $class::primaryKey();
@@ -154,11 +154,11 @@ class ActiveDataProvider extends BaseDataProvider
 	 */
 	protected function prepareTotalCount()
 	{
-		if (!$this->query instanceof Query) {
-			throw new InvalidConfigException('The "query" property must be an instance of Query or its subclass.');
+		if (!$this->query instanceof QueryInterface) {
+			throw new InvalidConfigException('The "query" property must be an instance of a class that implements the QueryInterface e.g. yii\db\Query or its subclasses.');
 		}
 		$query = clone $this->query;
-		return (int) $query->limit(-1)->offset(-1)->count('*', $this->db);
+		return (int) $query->limit(-1)->offset(-1)->orderBy([])->count('*', $this->db);
 	}
 
 	/**
@@ -167,7 +167,7 @@ class ActiveDataProvider extends BaseDataProvider
 	public function setSort($value)
 	{
 		parent::setSort($value);
-		if (($sort = $this->getSort()) !== false && empty($sort->attributes) && $this->query instanceof ActiveQuery) {
+		if (($sort = $this->getSort()) !== false && empty($sort->attributes) && $this->query instanceof ActiveQueryInterface) {
 			/** @var Model $model */
 			$model = new $this->query->modelClass;
 			foreach ($model->attributes() as $attribute) {

framework/yii/db/ActiveQuery.php

@@ -7,12 +7,13 @@
  */
 
 namespace yii\db;
+use yii\ar\ActiveQueryInterface;
+use yii\ar\ActiveQueryTrait;
 
 /**
  * ActiveQuery represents a DB query associated with an Active Record class.
  *
- * ActiveQuery instances are usually created by [[ActiveRecord::find()]], [[ActiveRecord::findBySql()]]
- * and [[ActiveRecord::count()]].
+ * ActiveQuery instances are usually created by [[ActiveRecord::find()]] and [[ActiveRecord::findBySql()]].
  *
  * ActiveQuery mainly provides the following methods to retrieve the query results:
  *
@@ -42,23 +43,13 @@ namespace yii\db;
  * ~~~
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
  * @since 2.0
  */
-class ActiveQuery extends Query
+class ActiveQuery extends Query implements ActiveQueryInterface
 {
-	/**
-	 * @var string the name of the ActiveRecord class.
-	 */
-	public $modelClass;
-	/**
-	 * @var array list of relations that this query should be performed with
-	 */
-	public $with;
-	/**
-	 * @var boolean whether to return each record as an array. If false (default), an object
-	 * of [[modelClass]] will be created to represent each record.
-	 */
-	public $asArray;
+	use ActiveQueryTrait;
+
 	/**
 	 * @var string the SQL statement to be executed for retrieving AR records.
 	 * This is set by [[ActiveRecord::findBySql()]].
@@ -67,25 +58,6 @@ class ActiveQuery extends Query
 
 
 	/**
-	 * PHP magic method.
-	 * This method allows calling static method defined in [[modelClass]] via this query object.
-	 * It is mainly implemented for supporting the feature of scope.
-	 * @param string $name the method name to be called
-	 * @param array $params the parameters passed to the method
-	 * @return mixed the method return result
-	 */
-	public function __call($name, $params)
-	{
-		if (method_exists($this->modelClass, $name)) {
-			array_unshift($params, $this);
-			call_user_func_array([$this->modelClass, $name], $params);
-			return $this;
-		} else {
-			return parent::__call($name, $params);
-		}
-	}
-
-	/**
 	 * Executes query and returns all results as an array.
 	 * @param Connection $db the DB connection used to create the DB command.
 	 * If null, the DB connection returned by [[modelClass]] will be used.
@@ -164,164 +136,4 @@ class ActiveQuery extends Query
 		}
 		return $db->createCommand($this->sql, $params);
 	}
-
-	/**
-	 * Sets the [[asArray]] property.
-	 * @param boolean $value whether to return the query results in terms of arrays instead of Active Records.
-	 * @return static the query object itself
-	 */
-	public function asArray($value = true)
-	{
-		$this->asArray = $value;
-		return $this;
-	}
-
-	/**
-	 * Specifies the relations with which this query should be performed.
-	 *
-	 * The parameters to this method can be either one or multiple strings, or a single array
-	 * of relation names and the optional callbacks to customize the relations.
-	 *
-	 * A relation name can refer to a relation defined in [[modelClass]]
-	 * or a sub-relation that stands for a relation of a related record.
-	 * For example, `orders.address` means the `address` relation defined
-	 * in the model class corresponding to the `orders` relation.
-	 *
-	 * The followings are some usage examples:
-	 *
-	 * ~~~
-	 * // find customers together with their orders and country
-	 * Customer::find()->with('orders', 'country')->all();
-	 * // find customers together with their orders and the orders' shipping address
-	 * Customer::find()->with('orders.address')->all();
-	 * // find customers together with their country and orders of status 1
-	 * Customer::find()->with([
-	 *     'orders' => function($query) {
-	 *         $query->andWhere('status = 1');
-	 *     },
-	 *     'country',
-	 * ])->all();
-	 * ~~~
-	 *
-	 * @return static the query object itself
-	 */
-	public function with()
-	{
-		$this->with = func_get_args();
-		if (isset($this->with[0]) && is_array($this->with[0])) {
-			// the parameter is given as an array
-			$this->with = $this->with[0];
-		}
-		return $this;
-	}
-
-	/**
-	 * Sets the [[indexBy]] property.
-	 * @param string|callable $column the name of the column by which the query results should be indexed by.
-	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
-	 * row or model data. The signature of the callable should be:
-	 *
-	 * ~~~
-	 * // $model is an AR instance when `asArray` is false,
-	 * // or an array of column values when `asArray` is true.
-	 * function ($model)
-	 * {
-	 *     // return the index value corresponding to $model
-	 * }
-	 * ~~~
-	 *
-	 * @return static the query object itself
-	 */
-	public function indexBy($column)
-	{
-		return parent::indexBy($column);
-	}
-
-	private function createModels($rows)
-	{
-		$models = [];
-		if ($this->asArray) {
-			if ($this->indexBy === null) {
-				return $rows;
-			}
-			foreach ($rows as $row) {
-				if (is_string($this->indexBy)) {
-					$key = $row[$this->indexBy];
-				} else {
-					$key = call_user_func($this->indexBy, $row);
-				}
-				$models[$key] = $row;
-			}
-		} else {
-			/** @var ActiveRecord $class */
-			$class = $this->modelClass;
-			if ($this->indexBy === null) {
-				foreach ($rows as $row) {
-					$models[] = $class::create($row);
-				}
-			} else {
-				foreach ($rows as $row) {
-					$model = $class::create($row);
-					if (is_string($this->indexBy)) {
-						$key = $model->{$this->indexBy};
-					} else {
-						$key = call_user_func($this->indexBy, $model);
-					}
-					$models[$key] = $model;
-				}
-			}
-		}
-		return $models;
-	}
-
-	private function populateRelations(&$models, $with)
-	{
-		$primaryModel = new $this->modelClass;
-		$relations = $this->normalizeRelations($primaryModel, $with);
-		foreach ($relations as $name => $relation) {
-			if ($relation->asArray === null) {
-				// inherit asArray from primary query
-				$relation->asArray = $this->asArray;
-			}
-			$relation->findWith($name, $models);
-		}
-	}
-
-	/**
-	 * @param ActiveRecord $model
-	 * @param array $with
-	 * @return ActiveRelation[]
-	 */
-	private function normalizeRelations($model, $with)
-	{
-		$relations = [];
-		foreach ($with as $name => $callback) {
-			if (is_integer($name)) {
-				$name = $callback;
-				$callback = null;
-			}
-			if (($pos = strpos($name, '.')) !== false) {
-				// with sub-relations
-				$childName = substr($name, $pos + 1);
-				$name = substr($name, 0, $pos);
-			} else {
-				$childName = null;
-			}
-
-			if (!isset($relations[$name])) {
-				$relation = $model->getRelation($name);
-				$relation->primaryModel = null;
-				$relations[$name] = $relation;
-			} else {
-				$relation = $relations[$name];
-			}
-
-			if (isset($childName)) {
-				$relation->with[$childName] = $callback;
-			} elseif ($callback !== null) {
-				call_user_func($callback, $relation);
-			}
-		}
-		return $relations;
-	}
 }

framework/yii/db/ActiveRecord.php

@@ -8,6 +8,7 @@
 
 namespace yii\db;
 
+use yii\ar\ActiveRelationInterface;
 use yii\base\InvalidConfigException;
 use yii\base\Model;
 use yii\base\InvalidParamException;
@@ -36,6 +37,7 @@ use yii\helpers\Inflector;
  * the key value is null). This property is read-only.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
  * @since 2.0
  */
 class ActiveRecord extends Model
@@ -252,7 +254,7 @@ class ActiveRecord extends Model
 
 	/**
 	 * Creates an [[ActiveQuery]] instance.
-	 * This method is called by [[find()]], [[findBySql()]] and [[count()]] to start a SELECT query.
+	 * This method is called by [[find()]], [[findBySql()]] to start a SELECT query.
 	 * You may override this method to return a customized query (e.g. `CustomerQuery` specified
 	 * written for querying `Customer` purpose.)
 	 * @return ActiveQuery the newly created [[ActiveQuery]] instance.
@@ -385,7 +387,7 @@ class ActiveRecord extends Model
 				return $this->_related[$name];
 			}
 			$value = parent::__get($name);
-			if ($value instanceof ActiveRelation) {
+			if ($value instanceof ActiveRelationInterface) {
 				return $this->_related[$name] = $value->multiple ? $value->all() : $value->one();
 			} else {
 				return $value;
@@ -474,7 +476,7 @@ class ActiveRecord extends Model
 	 */
 	public function hasOne($class, $link)
 	{
-		return new ActiveRelation([
+		return $this->createActiveRelation([
 			'modelClass' => $class,
 			'primaryModel' => $this,
 			'link' => $link,
@@ -512,7 +514,7 @@ class ActiveRecord extends Model
 	 */
 	public function hasMany($class, $link)
 	{
-		return new ActiveRelation([
+		return $this->createActiveRelation([
 			'modelClass' => $class,
 			'primaryModel' => $this,
 			'link' => $link,
@@ -521,6 +523,18 @@ class ActiveRecord extends Model
 	}
 
 	/**
+	 * Creates an [[ActiveRelation]] instance.
+	 * This method is called by [[hasOne()]] and [[hasMany()]] to create a relation instance.
+	 * You may override this method to return a customized relation.
+	 * @param array $config the configuration passed to the ActiveRelation class.
+	 * @return ActiveRelation the newly created [[ActiveRelation]] instance.
+	 */
+	protected function createActiveRelation($config = [])
+	{
+		return new ActiveRelation($config);
+	}
+
+	/**
 	 * Populates the named relation with the related records.
 	 * Note that this method does not check if the relation exists or not.
 	 * @param string $name the relation name (case-sensitive)
@@ -1283,7 +1297,7 @@ class ActiveRecord extends Model
 		$getter = 'get' . $name;
 		try {
 			$relation = $this->$getter();
-			if ($relation instanceof ActiveRelation) {
+			if ($relation instanceof ActiveRelationInterface) {
 				return $relation;
 			} else {
 				return null;

framework/yii/db/ActiveRelation.php

@@ -7,8 +7,8 @@
  */
 
 namespace yii\db;
-
-use yii\base\InvalidConfigException;
+use yii\ar\ActiveRelationInterface;
+use yii\ar\ActiveRelationTrait;
 
 /**
  * ActiveRelation represents a relation between two Active Record classes.
@@ -22,63 +22,16 @@ use yii\base\InvalidConfigException;
  *
  * If a relation involves a pivot table, it may be specified by [[via()]] or [[viaTable()]] method.
  *
+ * @property array|ActiveRelation $via the query associated with the pivot table. Please call [[via()]]
+ * or [[viaTable()]] to set this property instead of directly setting it.
+ *
  * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
  * @since 2.0
  */
-class ActiveRelation extends ActiveQuery
+class ActiveRelation extends ActiveQuery implements ActiveRelationInterface
 {
-	/**
-	 * @var boolean whether this relation should populate all query results into AR instances.
-	 * If false, only the first row of the results will be retrieved.
-	 */
-	public $multiple;
-	/**
-	 * @var ActiveRecord the primary model that this relation is associated with.
-	 * This is used only in lazy loading with dynamic query options.
-	 */
-	public $primaryModel;
-	/**
-	 * @var array the columns of the primary and foreign tables that establish the relation.
-	 * The array keys must be columns of the table for this relation, and the array values
-	 * must be the corresponding columns from the primary table.
-	 * Do not prefix or quote the column names as they will be done automatically by Yii.
-	 */
-	public $link;
-	/**
-	 * @var array|ActiveRelation the query associated with the pivot table. Please call [[via()]]
-	 * or [[viaTable()]] to set this property instead of directly setting it.
-	 */
-	public $via;
-
-	/**
-	 * Clones internal objects.
-	 */
-	public function __clone()
-	{
-		// make a clone of "via" object so that the same query object can be reused multiple times
-		if (is_object($this->via)) {
-			$this->via = clone $this->via;
-		} elseif (is_array($this->via)) {
-			$this->via = [$this->via[0], clone $this->via[1]];
-		}
-	}
-
-	/**
-	 * Specifies the relation associated with the pivot table.
-	 * @param string $relationName the relation name. This refers to a relation declared in [[primaryModel]].
-	 * @param callable $callable a PHP callback for customizing the relation associated with the pivot table.
-	 * Its signature should be `function($query)`, where `$query` is the query to be customized.
-	 * @return static the relation object itself.
-	 */
-	public function via($relationName, $callable = null)
-	{
-		$relation = $this->primaryModel->getRelation($relationName);
-		$this->via = [$relationName, $relation];
-		if ($callable !== null) {
-			call_user_func($callable, $relation);
-		}
-		return $this;
-	}
+	use ActiveRelationTrait;
 
 	/**
 	 * Specifies the pivot table.
@@ -139,179 +92,4 @@ class ActiveRelation extends ActiveQuery
 		}
 		return parent::createCommand($db);
 	}
-
-	/**
-	 * Finds the related records and populates them into the primary models.
-	 * This method is internally used by [[ActiveQuery]]. Do not call it directly.
-	 * @param string $name the relation name
-	 * @param array $primaryModels primary models
-	 * @return array the related models
-	 * @throws InvalidConfigException
-	 */
-	public function findWith($name, &$primaryModels)
-	{
-		if (!is_array($this->link)) {
-			throw new InvalidConfigException('Invalid link: it must be an array of key-value pairs.');
-		}
-
-		if ($this->via instanceof self) {
-			// via pivot table
-			/** @var ActiveRelation $viaQuery */
-			$viaQuery = $this->via;
-			$viaModels = $viaQuery->findPivotRows($primaryModels);
-			$this->filterByModels($viaModels);
-		} elseif (is_array($this->via)) {
-			// via relation
-			/** @var ActiveRelation $viaQuery */
-			list($viaName, $viaQuery) = $this->via;
-			$viaQuery->primaryModel = null;
-			$viaModels = $viaQuery->findWith($viaName, $primaryModels);
-			$this->filterByModels($viaModels);
-		} else {
-			$this->filterByModels($primaryModels);
-		}
-
-		if (count($primaryModels) === 1 && !$this->multiple) {
-			$model = $this->one();
-			foreach ($primaryModels as $i => $primaryModel) {
-				if ($primaryModel instanceof ActiveRecord) {
-					$primaryModel->populateRelation($name, $model);
-				} else {
-					$primaryModels[$i][$name] = $model;
-				}
-			}
-			return [$model];
-		} else {
-			$models = $this->all();
-			if (isset($viaModels, $viaQuery)) {
-				$buckets = $this->buildBuckets($models, $this->link, $viaModels, $viaQuery->link);
-			} else {
-				$buckets = $this->buildBuckets($models, $this->link);
-			}
-
-			$link = array_values(isset($viaQuery) ? $viaQuery->link : $this->link);
-			foreach ($primaryModels as $i => $primaryModel) {
-				$key = $this->getModelKey($primaryModel, $link);
-				$value = isset($buckets[$key]) ? $buckets[$key] : ($this->multiple ? [] : null);
-				if ($primaryModel instanceof ActiveRecord) {
-					$primaryModel->populateRelation($name, $value);
-				} else {
-					$primaryModels[$i][$name] = $value;
-				}
-			}
-			return $models;
-		}
-	}
-
-	/**
-	 * @param array $models
-	 * @param array $link
-	 * @param array $viaModels
-	 * @param array $viaLink
-	 * @return array
-	 */
-	private function buildBuckets($models, $link, $viaModels = null, $viaLink = null)
-	{
-		$buckets = [];
-		$linkKeys = array_keys($link);
-		foreach ($models as $i => $model) {
-			$key = $this->getModelKey($model, $linkKeys);
-			if ($this->indexBy !== null) {
-				$buckets[$key][$i] = $model;
-			} else {
-				$buckets[$key][] = $model;
-			}
-		}
-
-		if ($viaModels !== null) {
-			$viaBuckets = [];
-			$viaLinkKeys = array_keys($viaLink);
-			$linkValues = array_values($link);
-			foreach ($viaModels as $viaModel) {
-				$key1 = $this->getModelKey($viaModel, $viaLinkKeys);
-				$key2 = $this->getModelKey($viaModel, $linkValues);
-				if (isset($buckets[$key2])) {
-					foreach ($buckets[$key2] as $i => $bucket) {
-						if ($this->indexBy !== null) {
-							$viaBuckets[$key1][$i] = $bucket;
-						} else {
-							$viaBuckets[$key1][] = $bucket;
-						}
-					}
-				}
-			}
-			$buckets = $viaBuckets;
-		}
-
-		if (!$this->multiple) {
-			foreach ($buckets as $i => $bucket) {
-				$buckets[$i] = reset($bucket);
-			}
-		}
-		return $buckets;
-	}
-
-	/**
-	 * @param ActiveRecord|array $model
-	 * @param array $attributes
-	 * @return string
-	 */
-	private function getModelKey($model, $attributes)
-	{
-		if (count($attributes) > 1) {
-			$key = [];
-			foreach ($attributes as $attribute) {
-				$key[] = $model[$attribute];
-			}
-			return serialize($key);
-		} else {
-			$attribute = reset($attributes);
-			return $model[$attribute];
-		}
-	}
-
-	/**
-	 * @param array $models
-	 */
-	private function filterByModels($models)
-	{
-		$attributes = array_keys($this->link);
-		$values = [];
-		if (count($attributes) === 1) {
-			// single key
-			$attribute = reset($this->link);
-			foreach ($models as $model) {
-				if (($value = $model[$attribute]) !== null) {
-					$values[] = $value;
-				}
-			}
-		} else {
-			// composite keys
-			foreach ($models as $model) {
-				$v = [];
-				foreach ($this->link as $attribute => $link) {
-					$v[$attribute] = $model[$link];
-				}
-				$values[] = $v;
-			}
-		}
-		$this->andWhere(['in', $attributes, array_unique($values, SORT_REGULAR)]);
-	}
-
-	/**
-	 * @param ActiveRecord[] $primaryModels
-	 * @return array
-	 */
-	private function findPivotRows($primaryModels)
-	{
-		if (empty($primaryModels)) {
-			return [];
-		}
-		$this->filterByModels($primaryModels);
-		/** @var ActiveRecord $primaryModel */
-		$primaryModel = reset($primaryModels);
-		$db = $primaryModel->getDb();
-		list ($sql, $params) = $db->getQueryBuilder()->build($this);
-		return $db->createCommand($sql, $params)->queryAll();
-	}
 }

framework/yii/db/Query.php

@@ -33,20 +33,12 @@ use yii\base\Component;
  * ~~~
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
  * @since 2.0
  */
-class Query extends Component
+class Query extends Component implements QueryInterface
 {
-	/**
-	 * Sort ascending
-	 * @see orderBy()
-	 */
-	const SORT_ASC = false;
-	/**
-	 * Sort descending
-	 * @see orderBy()
-	 */
-	const SORT_DESC = true;
+	use QueryTrait;
 
 	/**
 	 * @var array the columns being selected. For example, `['id', 'name']`.
@@ -71,28 +63,6 @@ class Query extends Component
 	 */
 	public $from;
 	/**
-	 * @var string|array query condition. This refers to the WHERE clause in a SQL statement.
-	 * For example, `age > 31 AND team = 1`.
-	 * @see where()
-	 */
-	public $where;
-	/**
-	 * @var integer maximum number of records to be returned. If not set or less than 0, it means no limit.
-	 */
-	public $limit;
-	/**
-	 * @var integer zero-based offset from where the records are to be returned. If not set or
-	 * less than 0, it means starting from the beginning.
-	 */
-	public $offset;
-	/**
-	 * @var array how to sort the query results. This is used to construct the ORDER BY clause in a SQL statement.
-	 * The array keys are the columns to be sorted by, and the array values are the corresponding sort directions which
-	 * can be either [[Query::SORT_ASC]] or [[Query::SORT_DESC]]. The array may also contain [[Expression]] objects.
-	 * If that is the case, the expressions will be converted into strings without any change.
-	 */
-	public $orderBy;
-	/**
 	 * @var array how to group the query results. For example, `['company', 'department']`.
 	 * This is used to construct the GROUP BY clause in a SQL statement.
 	 */
@@ -130,12 +100,6 @@ class Query extends Component
 	 * For example, `[':name' => 'Dan', ':age' => 31]`.
 	 */
 	public $params;
-	/**
-	 * @var string|callable $column the name of the column by which the query results should be indexed by.
-	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
-	 * row data. For more details, see [[indexBy()]]. This property is only used by [[all()]].
-	 */
-	public $indexBy;
 
 
 	/**
@@ -154,27 +118,6 @@ class Query extends Component
 	}
 
 	/**
-	 * Sets the [[indexBy]] property.
-	 * @param string|callable $column the name of the column by which the query results should be indexed by.
-	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
-	 * row data. The signature of the callable should be:
-	 *
-	 * ~~~
-	 * function ($row)
-	 * {
-	 *     // return the index value corresponding to $row
-	 * }
-	 * ~~~
-	 *
-	 * @return static the query object itself
-	 */
-	public function indexBy($column)
-	{
-		$this->indexBy = $column;
-		return $this;
-	}
-
-	/**
 	 * Executes the query and returns all results as an array.
 	 * @param Connection $db the database connection used to generate the SQL statement.
 	 * If this parameter is not given, the `db` application component will be used.
@@ -239,7 +182,7 @@ class Query extends Component
 	 * @param string $q the COUNT expression. Defaults to '*'.
 	 * Make sure you properly quote column names in the expression.
 	 * @param Connection $db the database connection used to generate the SQL statement.
-	 * If this parameter is not given, the `db` application component will be used.
+	 * If this parameter is not given (or null), the `db` application component will be used.
 	 * @return integer number of records
 	 */
 	public function count($q = '*', $db = null)
@@ -653,83 +596,6 @@ class Query extends Component
 	}
 
 	/**
-	 * Sets the ORDER BY part of the query.
-	 * @param string|array $columns the columns (and the directions) to be ordered by.
-	 * Columns can be specified in either a string (e.g. "id ASC, name DESC") or an array
-	 * (e.g. `['id' => Query::SORT_ASC, 'name' => Query::SORT_DESC]`).
-	 * The method will automatically quote the column names unless a column contains some parenthesis
-	 * (which means the column contains a DB expression).
-	 * @return static the query object itself
-	 * @see addOrderBy()
-	 */
-	public function orderBy($columns)
-	{
-		$this->orderBy = $this->normalizeOrderBy($columns);
-		return $this;
-	}
-
-	/**
-	 * Adds additional ORDER BY columns to the query.
-	 * @param string|array $columns the columns (and the directions) to be ordered by.
-	 * Columns can be specified in either a string (e.g. "id ASC, name DESC") or an array
-	 * (e.g. `['id' => Query::SORT_ASC, 'name' => Query::SORT_DESC]`).
-	 * The method will automatically quote the column names unless a column contains some parenthesis
-	 * (which means the column contains a DB expression).
-	 * @return static the query object itself
-	 * @see orderBy()
-	 */
-	public function addOrderBy($columns)
-	{
-		$columns = $this->normalizeOrderBy($columns);
-		if ($this->orderBy === null) {
-			$this->orderBy = $columns;
-		} else {
-			$this->orderBy = array_merge($this->orderBy, $columns);
-		}
-		return $this;
-	}
-
-	protected function normalizeOrderBy($columns)
-	{
-		if (is_array($columns)) {
-			return $columns;
-		} else {
-			$columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY);
-			$result = [];
-			foreach ($columns as $column) {
-				if (preg_match('/^(.*?)\s+(asc|desc)$/i', $column, $matches)) {
-					$result[$matches[1]] = strcasecmp($matches[2], 'desc') ? self::SORT_ASC : self::SORT_DESC;
-				} else {
-					$result[$column] = self::SORT_ASC;
-				}
-			}
-			return $result;
-		}
-	}
-
-	/**
-	 * Sets the LIMIT part of the query.
-	 * @param integer $limit the limit. Use null or negative value to disable limit.
-	 * @return static the query object itself
-	 */
-	public function limit($limit)
-	{
-		$this->limit = $limit;
-		return $this;
-	}
-
-	/**
-	 * Sets the OFFSET part of the query.
-	 * @param integer $offset the offset. Use null or negative value to disable offset.
-	 * @return static the query object itself
-	 */
-	public function offset($offset)
-	{
-		$this->offset = $offset;
-		return $this;
-	}
-
-	/**
 	 * Appends a SQL statement using UNION operator.
 	 * @param string|Query $sql the SQL statement to be appended using UNION
 	 * @return static the query object itself

framework/yii/db/QueryBuilder.php

@@ -683,7 +683,7 @@ class QueryBuilder extends \yii\base\Object
 			if (is_object($direction)) {
 				$orders[] = (string)$direction;
 			} else {
-				$orders[] = $this->db->quoteColumnName($name) . ($direction === Query::SORT_DESC ? ' DESC' : '');
+				$orders[] = $this->db->quoteColumnName($name) . ($direction === SORT_DESC ? ' DESC' : '');
 			}
 		}
 

framework/yii/db/QueryInterface.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db;
+
+/**
+ * The QueryInterface defines the minimum set of methods to be implemented by a database query.
+ *
+ * The default implementation of this interface is provided by [[QueryTrait]].
+ *
+ * It has support for getting [[one]] instance or [[all]].
+ * Allows pagination via [[limit]] and [[offset]].
+ * Sorting is supported via [[orderBy]] and items can be limited to match some conditions using [[where]].
+ *
+ * By calling [[createCommand()]], we can get a [[Command]] instance which can be further
+ * used to perform/execute the DB query against a database.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+interface QueryInterface
+{
+	/**
+	 * Executes the query and returns all results as an array.
+	 * @param Connection $db the database connection used to execute the query.
+	 * If this parameter is not given, the `db` application component will be used.
+	 * @return array the query results. If the query results in nothing, an empty array will be returned.
+	 */
+	public function all($db = null);
+
+	/**
+	 * Executes the query and returns a single row of result.
+	 * @param Connection $db the database connection used to execute the query.
+	 * If this parameter is not given, the `db` application component will be used.
+	 * @return array|boolean the first row (in terms of an array) of the query result. False is returned if the query
+	 * results in nothing.
+	 */
+	public function one($db = null);
+
+	/**
+	 * Returns the number of records.
+	 * @param string $q the COUNT expression. Defaults to '*'.
+	 * @param Connection $db the database connection used to execute the query.
+	 * If this parameter is not given, the `db` application component will be used.
+	 * @return integer number of records
+	 */
+	public function count($q = '*', $db = null);
+
+	/**
+	 * Returns a value indicating whether the query result contains any row of data.
+	 * @param Connection $db the database connection used to execute the query.
+	 * If this parameter is not given, the `db` application component will be used.
+	 * @return boolean whether the query result contains any row of data.
+	 */
+	public function exists($db = null);
+
+	/**
+	 * Sets the [[indexBy]] property.
+	 * @param string|callable $column the name of the column by which the query results should be indexed by.
+	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
+	 * row data. The signature of the callable should be:
+	 *
+	 * ~~~
+	 * function ($row)
+	 * {
+	 *     // return the index value corresponding to $row
+	 * }
+	 * ~~~
+	 *
+	 * @return static the query object itself
+	 */
+	public function indexBy($column);
+
+	/**
+	 * Sets the WHERE part of the query.
+	 *
+	 * The method requires a $condition parameter.
+	 *
+	 * The $condition parameter should be an array in one of the following two formats:
+	 *
+	 * - hash format: `['column1' => value1, 'column2' => value2, ...]`
+	 * - operator format: `[operator, operand1, operand2, ...]`
+	 *
+	 * A condition in hash format represents the following SQL expression in general:
+	 * `column1=value1 AND column2=value2 AND ...`. In case when a value is an array,
+	 * an `IN` expression will be generated. And if a value is null, `IS NULL` will be used
+	 * in the generated expression. Below are some examples:
+	 *
+	 * - `['type' => 1, 'status' => 2]` generates `(type = 1) AND (status = 2)`.
+	 * - `['id' => [1, 2, 3], 'status' => 2]` generates `(id IN (1, 2, 3)) AND (status = 2)`.
+	 * - `['status' => null] generates `status IS NULL`.
+	 *
+	 * A condition in operator format generates the SQL expression according to the specified operator, which
+	 * can be one of the followings:
+	 *
+	 * - `and`: the operands should be concatenated together using `AND`. For example,
+	 * `['and', 'id=1', 'id=2']` will generate `id=1 AND id=2`. If an operand is an array,
+	 * it will be converted into a string using the rules described here. For example,
+	 * `['and', 'type=1', ['or', 'id=1', 'id=2']]` will generate `type=1 AND (id=1 OR id=2)`.
+	 * The method will NOT do any quoting or escaping.
+	 *
+	 * - `or`: similar to the `and` operator except that the operands are concatenated using `OR`.
+	 *
+	 * - `between`: operand 1 should be the column name, and operand 2 and 3 should be the
+	 * starting and ending values of the range that the column is in.
+	 * For example, `['between', 'id', 1, 10]` will generate `id BETWEEN 1 AND 10`.
+	 *
+	 * - `not between`: similar to `between` except the `BETWEEN` is replaced with `NOT BETWEEN`
+	 * in the generated condition.
+	 *
+	 * - `in`: operand 1 should be a column or DB expression, and operand 2 be an array representing
+	 * the range of the values that the column or DB expression should be in. For example,
+	 * `['in', 'id', [1, 2, 3]]` will generate `id IN (1, 2, 3)`.
+	 * The method will properly quote the column name and escape values in the range.
+	 *
+	 * - `not in`: similar to the `in` operator except that `IN` is replaced with `NOT IN` in the generated condition.
+	 *
+	 * - `like`: operand 1 should be a column or DB expression, and operand 2 be a string or an array representing
+	 * the values that the column or DB expression should be like.
+	 * For example, `['like', 'name', '%tester%']` will generate `name LIKE '%tester%'`.
+	 * When the value range is given as an array, multiple `LIKE` predicates will be generated and concatenated
+	 * using `AND`. For example, `['like', 'name', ['%test%', '%sample%']]` will generate
+	 * `name LIKE '%test%' AND name LIKE '%sample%'`.
+	 * The method will properly quote the column name and escape values in the range.
+	 *
+	 * - `or like`: similar to the `like` operator except that `OR` is used to concatenate the `LIKE`
+	 * predicates when operand 2 is an array.
+	 *
+	 * - `not like`: similar to the `like` operator except that `LIKE` is replaced with `NOT LIKE`
+	 * in the generated condition.
+	 *
+	 * - `or not like`: similar to the `not like` operator except that `OR` is used to concatenate
+	 * the `NOT LIKE` predicates.
+	 *
+	 * @param array $condition the conditions that should be put in the WHERE part.
+	 * @return static the query object itself
+	 * @see andWhere()
+	 * @see orWhere()
+	 */
+	public function where($condition);
+
+	/**
+	 * Adds an additional WHERE condition to the existing one.
+	 * The new condition and the existing one will be joined using the 'AND' operator.
+	 * @param string|array $condition the new WHERE condition. Please refer to [[where()]]
+	 * on how to specify this parameter.
+	 * @return static the query object itself
+	 * @see where()
+	 * @see orWhere()
+	 */
+	public function andWhere($condition);
+
+	/**
+	 * Adds an additional WHERE condition to the existing one.
+	 * The new condition and the existing one will be joined using the 'OR' operator.
+	 * @param string|array $condition the new WHERE condition. Please refer to [[where()]]
+	 * on how to specify this parameter.
+	 * @return static the query object itself
+	 * @see where()
+	 * @see andWhere()
+	 */
+	public function orWhere($condition);
+
+	/**
+	 * Sets the ORDER BY part of the query.
+	 * @param string|array $columns the columns (and the directions) to be ordered by.
+	 * Columns can be specified in either a string (e.g. "id ASC, name DESC") or an array
+	 * (e.g. `['id' => SORT_ASC, 'name' => SORT_DESC]`).
+	 * The method will automatically quote the column names unless a column contains some parenthesis
+	 * (which means the column contains a DB expression).
+	 * @return static the query object itself
+	 * @see addOrderBy()
+	 */
+	public function orderBy($columns);
+
+	/**
+	 * Adds additional ORDER BY columns to the query.
+	 * @param string|array $columns the columns (and the directions) to be ordered by.
+	 * Columns can be specified in either a string (e.g. "id ASC, name DESC") or an array
+	 * (e.g. `['id' => SORT_ASC, 'name' => SORT_DESC]`).
+	 * The method will automatically quote the column names unless a column contains some parenthesis
+	 * (which means the column contains a DB expression).
+	 * @return static the query object itself
+	 * @see orderBy()
+	 */
+	public function addOrderBy($columns);
+
+	/**
+	 * Sets the LIMIT part of the query.
+	 * @param integer $limit the limit. Use null or negative value to disable limit.
+	 * @return static the query object itself
+	 */
+	public function limit($limit);
+
+	/**
+	 * Sets the OFFSET part of the query.
+	 * @param integer $offset the offset. Use null or negative value to disable offset.
+	 * @return static the query object itself
+	 */
+	public function offset($offset);
+}
\ No newline at end of file

framework/yii/db/QueryTrait.php

+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\db;
+
+/**
+ * The BaseQuery trait represents the minimum method set of a database Query.
+ *
+ * It has support for getting [[one]] instance or [[all]].
+ * Allows pagination via [[limit]] and [[offset]].
+ * Sorting is supported via [[orderBy]] and items can be limited to match some conditions unsing [[where]].
+ *
+ * By calling [[createCommand()]], we can get a [[Command]] instance which can be further
+ * used to perform/execute the DB query against a database.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+trait QueryTrait
+{
+	/**
+	 * @var string|array query condition. This refers to the WHERE clause in a SQL statement.
+	 * For example, `age > 31 AND team = 1`.
+	 * @see where()
+	 */
+	public $where;
+	/**
+	 * @var integer maximum number of records to be returned. If not set or less than 0, it means no limit.
+	 */
+	public $limit;
+	/**
+	 * @var integer zero-based offset from where the records are to be returned. If not set or
+	 * less than 0, it means starting from the beginning.
+	 */
+	public $offset;
+	/**
+	 * @var array how to sort the query results. This is used to construct the ORDER BY clause in a SQL statement.
+	 * The array keys are the columns to be sorted by, and the array values are the corresponding sort directions which
+	 * can be either [SORT_ASC](http://php.net/manual/en/array.constants.php#constant.sort-asc)
+	 * or [SORT_DESC](http://php.net/manual/en/array.constants.php#constant.sort-desc).
+	 * The array may also contain [[Expression]] objects. If that is the case, the expressions
+	 * will be converted into strings without any change.
+	 */
+	public $orderBy;
+	/**
+	 * @var string|callable $column the name of the column by which the query results should be indexed by.
+	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
+	 * row data. For more details, see [[indexBy()]]. This property is only used by [[all()]].
+	 */
+	public $indexBy;
+
+	/**
+	 * Sets the [[indexBy]] property.
+	 * @param string|callable $column the name of the column by which the query results should be indexed by.
+	 * This can also be a callable (e.g. anonymous function) that returns the index value based on the given
+	 * row data. The signature of the callable should be:
+	 *
+	 * ~~~
+	 * function ($row)
+	 * {
+	 *     // return the index value corresponding to $row
+	 * }
+	 * ~~~
+	 *
+	 * @return static the query object itself
+	 */
+	public function indexBy($column)
+	{
+		$this->indexBy = $column;
+		return $this;
+	}
+
+	/**
+	 * Sets the WHERE part of the query.
+	 *
+	 * See [[QueryInterface::where()]] for detailed documentation.
+	 *
+	 * @param array $condition the conditions that should be put in the WHERE part.
+	 * @return static the query object itself
+	 * @see andWhere()
+	 * @see orWhere()
+	 */
+	public function where($condition)
+	{
+		$this->where = $condition;
+		return $this;
+	}
+
+	/**
+	 * Adds an additional WHERE condition to the existing one.
+	 * The new condition and the existing one will be joined using the 'AND' operator.
+	 * @param string|array $condition the new WHERE condition. Please refer to [[where()]]
+	 * on how to specify this parameter.
+	 * @return static the query object itself
+	 * @see where()
+	 * @see orWhere()
+	 */
+	public function andWhere($condition)
+	{
+		if ($this->where === null) {
+			$this->where = $condition;
+		} else {
+			$this->where = ['and', $this->where, $condition];
+		}
+		return $this;
+	}
+
+	/**
+	 * Adds an additional WHERE condition to the existing one.
+	 * The new condition and the existing one will be joined using the 'OR' operator.
+	 * @param string|array $condition the new WHERE condition. Please refer to [[where()]]
+	 * on how to specify this parameter.
+	 * @return static the query object itself
+	 * @see where()
+	 * @see andWhere()
+	 */
+	public function orWhere($condition)
+	{
+		if ($this->where === null) {
+			$this->where = $condition;
+		} else {
+			$this->where = ['or', $this->where, $condition];
+		}
+		return $this;
+	}
+
+	/**
+	 * Sets the ORDER BY part of the query.
+	 * @param string|array $columns the columns (and the directions) to be ordered by.
+	 * Columns can be specified in either a string (e.g. "id ASC, name DESC") or an array
+	 * (e.g. `['id' => SORT_ASC, 'name' => SORT_DESC]`).
+	 * The method will automatically quote the column names unless a column contains some parenthesis
+	 * (which means the column contains a DB expression).
+	 * @return static the query object itself
+	 * @see addOrderBy()
+	 */
+	public function orderBy($columns)
+	{
+		$this->orderBy = $this->normalizeOrderBy($columns);
+		return $this;
+	}
+
+	/**
+	 * Adds additional ORDER BY columns to the query.
+	 * @param string|array $columns the columns (and the directions) to be ordered by.
+	 * Columns can be specified in either a string (e.g. "id ASC, name DESC") or an array
+	 * (e.g. `['id' => SORT_ASC, 'name' => SORT_DESC]`).
+	 * The method will automatically quote the column names unless a column contains some parenthesis
+	 * (which means the column contains a DB expression).
+	 * @return static the query object itself
+	 * @see orderBy()
+	 */
+	public function addOrderBy($columns)
+	{
+		$columns = $this->normalizeOrderBy($columns);
+		if ($this->orderBy === null) {
+			$this->orderBy = $columns;
+		} else {
+			$this->orderBy = array_merge($this->orderBy, $columns);
+		}
+		return $this;
+	}
+
+	protected function normalizeOrderBy($columns)
+	{
+		if (is_array($columns)) {
+			return $columns;
+		} else {
+			$columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY);
+			$result = [];
+			foreach ($columns as $column) {
+				if (preg_match('/^(.*?)\s+(asc|desc)$/i', $column, $matches)) {
+					$result[$matches[1]] = strcasecmp($matches[2], 'desc') ? SORT_ASC : SORT_DESC;
+				} else {
+					$result[$column] = SORT_ASC;
+				}
+			}
+			return $result;
+		}
+	}
+
+	/**
+	 * Sets the LIMIT part of the query.
+	 * @param integer $limit the limit. Use null or negative value to disable limit.
+	 * @return static the query object itself
+	 */
+	public function limit($limit)
+	{
+		$this->limit = $limit;
+		return $this;
+	}
+
+	/**
+	 * Sets the OFFSET part of the query.
+	 * @param integer $offset the offset. Use null or negative value to disable offset.
+	 * @return static the query object itself
+	 */
+	public function offset($offset)
+	{
+		$this->offset = $offset;
+		return $this;
+	}
+}
\ No newline at end of file

tests/unit/framework/data/ActiveDataProviderTest.php

@@ -10,6 +10,8 @@ namespace yiiunit\framework\data;
 use yii\data\ActiveDataProvider;
 use yii\db\Query;
 use yiiunit\data\ar\ActiveRecord;
+use yiiunit\data\ar\Customer;
+use yiiunit\data\ar\Item;
 use yiiunit\framework\db\DatabaseTestCase;
 use yiiunit\data\ar\Order;
 
@@ -18,6 +20,7 @@ use yiiunit\data\ar\Order;
  * @since 2.0
  *
  * @group data
+ * @group db
  */
 class ActiveDataProviderTest extends DatabaseTestCase
 {
@@ -35,6 +38,8 @@ class ActiveDataProviderTest extends DatabaseTestCase
 		$orders = $provider->getModels();
 		$this->assertEquals(3, count($orders));
 		$this->assertTrue($orders[0] instanceof Order);
+		$this->assertTrue($orders[1] instanceof Order);
+		$this->assertTrue($orders[2] instanceof Order);
 		$this->assertEquals([1, 2, 3], $provider->getKeys());
 
 		$provider = new ActiveDataProvider([
@@ -47,6 +52,75 @@ class ActiveDataProviderTest extends DatabaseTestCase
 		$this->assertEquals(2, count($orders));
 	}
 
+	public function testActiveRelation()
+	{
+		/** @var Customer $customer */
+		$customer = Customer::find(2);
+		$provider = new ActiveDataProvider([
+			'query' => $customer->getOrders(),
+		]);
+		$orders = $provider->getModels();
+		$this->assertEquals(2, count($orders));
+		$this->assertTrue($orders[0] instanceof Order);
+		$this->assertTrue($orders[1] instanceof Order);
+		$this->assertEquals([2, 3], $provider->getKeys());
+
+		$provider = new ActiveDataProvider([
+			'query' => $customer->getOrders(),
+			'pagination' => [
+				'pageSize' => 1,
+			]
+		]);
+		$orders = $provider->getModels();
+		$this->assertEquals(1, count($orders));
+	}
+
+	public function testActiveRelationVia()
+	{
+		/** @var Order $order */
+		$order = Order::find(2);
+		$provider = new ActiveDataProvider([
+			'query' => $order->getItems(),
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(3, count($items));
+		$this->assertTrue($items[0] instanceof Item);
+		$this->assertTrue($items[1] instanceof Item);
+		$this->assertTrue($items[2] instanceof Item);
+		$this->assertEquals([3, 4, 5], $provider->getKeys());
+
+		$provider = new ActiveDataProvider([
+			'query' => $order->getItems(),
+			'pagination' => [
+				'pageSize' => 2,
+			]
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(2, count($items));
+	}
+
+	public function testActiveRelationViaTable()
+	{
+		/** @var Order $order */
+		$order = Order::find(1);
+		$provider = new ActiveDataProvider([
+			'query' => $order->getBooks(),
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(2, count($items));
+		$this->assertTrue($items[0] instanceof Item);
+		$this->assertTrue($items[1] instanceof Item);
+
+		$provider = new ActiveDataProvider([
+			'query' => $order->getBooks(),
+			'pagination' => [
+				'pageSize' => 1,
+			]
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(1, count($items));
+	}
+
 	public function testQuery()
 	{
 		$query = new Query;

tests/unit/framework/db/ActiveRecordTest.php

@@ -119,10 +119,19 @@ class ActiveRecordTest extends DatabaseTestCase
 	{
 		/** @var Customer $customer */
 		$customer = Customer::find(2);
+		$this->assertFalse($customer->isRelationPopulated('orders'));
 		$orders = $customer->orders;
+		$this->assertTrue($customer->isRelationPopulated('orders'));
 		$this->assertEquals(2, count($orders));
+		$this->assertEquals(1, count($customer->populatedRelations));
 
+		/** @var Customer $customer */
+		$customer = Customer::find(2);
+		$this->assertFalse($customer->isRelationPopulated('orders'));
 		$orders = $customer->getOrders()->where('id=3')->all();
+		$this->assertFalse($customer->isRelationPopulated('orders'));
+		$this->assertEquals(0, count($customer->populatedRelations));
+
 		$this->assertEquals(1, count($orders));
 		$this->assertEquals(3, $orders[0]->id);
 	}
@@ -131,8 +140,15 @@ class ActiveRecordTest extends DatabaseTestCase
 	{
 		$customers = Customer::find()->with('orders')->all();
 		$this->assertEquals(3, count($customers));
+		$this->assertTrue($customers[0]->isRelationPopulated('orders'));
+		$this->assertTrue($customers[1]->isRelationPopulated('orders'));
 		$this->assertEquals(1, count($customers[0]->orders));
 		$this->assertEquals(2, count($customers[1]->orders));
+
+		$customer = Customer::find()->with('orders')->one();
+		$this->assertTrue($customer->isRelationPopulated('orders'));
+		$this->assertEquals(1, count($customer->orders));
+		$this->assertEquals(1, count($customer->populatedRelations));
 	}
 
 	public function testFindLazyVia()

tests/unit/framework/db/QueryTest.php

@@ -86,19 +86,19 @@ class QueryTest extends DatabaseTestCase
 	{
 		$query = new Query;
 		$query->orderBy('team');
-		$this->assertEquals(['team' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC], $query->orderBy);
 
 		$query->addOrderBy('company');
-		$this->assertEquals(['team' => false, 'company' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_ASC], $query->orderBy);
 
 		$query->addOrderBy('age');
-		$this->assertEquals(['team' => false, 'company' => false, 'age' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_ASC, 'age' => SORT_ASC], $query->orderBy);
 
-		$query->addOrderBy(['age' => true]);
-		$this->assertEquals(['team' => false, 'company' => false, 'age' => true], $query->orderBy);
+		$query->addOrderBy(['age' => SORT_DESC]);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_ASC, 'age' => SORT_DESC], $query->orderBy);
 
 		$query->addOrderBy('age ASC, company DESC');
-		$this->assertEquals(['team' => false, 'company' => true, 'age' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_DESC, 'age' => SORT_ASC], $query->orderBy);
 	}
 
 	public function testLimitOffset()

tests/unit/framework/db/cubrid/CubridActiveDataProviderTest.php

+<?php
+namespace yiiunit\framework\db\cubrid;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group cubrid
+ * @group data
+ */
+class CubridActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'cubrid';
+}

tests/unit/framework/db/mssql/MssqlActiveDataProviderTest.php

+<?php
+namespace yiiunit\framework\db\mssql;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group mssql
+ * @group data
+ */
+class MssqlActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'sqlsrv';
+}

tests/unit/framework/db/pgsql/PostgreSQLActiveDataProviderTest.php

+<?php
+namespace yiiunit\framework\db\pgsql;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group pgsql
+ * @group data
+ */
+class PostgreSQLActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'pgsql';
+}

tests/unit/framework/db/sqlite/SqliteActiveDataProviderTest.php

+<?php
+namespace yiiunit\framework\db\sqlite;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group sqlite
+ * @group data
+ */
+class SqliteActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'sqlite';
+}