diff --git a/framework/db/ar/ActiveQuery.php b/framework/db/ar/ActiveQuery.php
index a35f932..e7d58be 100644
--- a/framework/db/ar/ActiveQuery.php
+++ b/framework/db/ar/ActiveQuery.php
@@ -66,27 +66,38 @@ class ActiveQuery extends BaseQuery
 	{
 		$command = $this->createCommand();
 		$rows = $command->queryAll();
+		if ($rows === array()) {
+			return array();
+		}
 		$models = $this->createModels($rows);
-		if (empty($this->with)) {
-			return $models;
+		if (!empty($this->with)) {
+			$this->fetchRelatedModels($models, $this->with);
 		}
+		return $models;
 	}
 
 	/**
 	 * Executes query and returns a single row of result.
-	 * @return ActiveRecord|array|boolean a single row of query result. Depending on the setting of [[asArray]],
-	 * the query result may be either an array or an ActiveRecord object. False will be returned
+	 * @return ActiveRecord|array|null a single row of query result. Depending on the setting of [[asArray]],
+	 * the query result may be either an array or an ActiveRecord object. Null will be returned
 	 * if the query results in nothing.
 	 */
 	public function one()
 	{
 		$command = $this->createCommand();
 		$row = $command->queryRow();
-		if ($row === false || $this->asArray) {
+		if ($row === false) {
+			return false;
+		} elseif ($this->asArray) {
 			return $row;
 		} else {
+			/** @var $class ActiveRecord */
 			$class = $this->modelClass;
-			return $class::create($row);
+			$model = $class::create($row);
+			if (!empty($this->with)) {
+				$this->fetchRelatedModels(array($model), $this->with);
+			}
+			return $model;
 		}
 	}
 
@@ -107,7 +118,8 @@ class ActiveQuery extends BaseQuery
 	 */
 	public function exists()
 	{
-		return $this->select(array(new Expression('1')))->value() !== false;
+		$this->select = array(new Expression('1'));
+		return $this->value() !== false;
 	}
 
 	/**
@@ -118,6 +130,7 @@ class ActiveQuery extends BaseQuery
 	 */
 	public function createCommand($db = null)
 	{
+		/** @var $modelClass ActiveRecord */
 		$modelClass = $this->modelClass;
 		if ($db === null) {
 			$db = $modelClass::getDbConnection();
@@ -139,10 +152,9 @@ class ActiveQuery extends BaseQuery
 			}
 			/** @var $qb QueryBuilder */
 			$qb = $db->getQueryBuilder();
-			return $db->createCommand($qb->build($this), $this->params);
-		} else {
-			return $db->createCommand($this->sql, $this->params);
+			$this->sql = $qb->build($this);
 		}
+		return $db->createCommand($this->sql, $this->params);
 	}
 
 	public function asArray($value = true)
@@ -173,55 +185,6 @@ class ActiveQuery extends BaseQuery
 		return $this;
 	}
 
-	protected function find()
-	{
-		$modelClass = $this->modelClass;
-		/**
-		 * @var \yii\db\dao\Connection $db
-		 */
-		$db = $modelClass::getDbConnection();
-		if ($this->sql === null) {
-			if ($this->from === null) {
-				$tableName = $modelClass::getTableSchema()->name;
-				$this->from = array($tableName);
-			}
-			foreach ($this->scopes as $name => $config) {
-				if (is_integer($name)) {
-					$modelClass::$config($this);
-				} else {
-					array_unshift($config, $this);
-					call_user_func_array(array($modelClass, $name), $config);
-				}
-			}
-			$this->sql = $db->getQueryBuilder()->build($this);
-		}
-		$command = $db->createCommand($this->sql, $this->params);
-		$rows = $command->queryAll();
-		$records = $this->createRecords($rows);
-		if ($records !== array()) {
-			foreach ($this->with as $name => $config) {
-				/** @var Relation $relation */
-				$relation = $model->$name();
-				foreach ($config as $p => $v) {
-					$relation->$p = $v;
-				}
-				if ($relation->asArray === null) {
-					// inherit asArray from parent query
-					$relation->asArray = $this->asArray;
-				}
-				$rs = $relation->findWith($records);
-				/*
-				foreach ($rs as $r) {
-					// find the matching parent record(s)
-					// insert into the parent records(s)
-				}
-				*/
-			}
-		}
-
-		return $records;
-	}
-
 	protected function createModels($rows)
 	{
 		$models = array();
@@ -248,4 +211,26 @@ class ActiveQuery extends BaseQuery
 		}
 		return $models;
 	}
+
+	protected function fetchRelatedModels(&$models, $relations)
+	{
+		// todo: normalize $relations
+		$primaryModel = new $this->modelClass;
+		foreach ($relations as $name => $properties) {
+			if (!method_exists($primaryModel, $name)) {
+				throw new Exception("Unknown relation: $name");
+			}
+			/** @var $relation ActiveRelation */
+			$relation = $primaryModel->$name();
+			$relation->primaryModel = null;
+			foreach ($properties as $p => $v) {
+				$relation->$p = $v;
+			}
+			if ($relation->asArray === null) {
+				// inherit asArray from primary query
+				$relation->asArray = $this->asArray;
+			}
+			$relation->findWith($name, $models);
+		}
+	}
 }
diff --git a/framework/db/ar/ActiveRecord.php b/framework/db/ar/ActiveRecord.php
index fccfb98..70566a9 100644
--- a/framework/db/ar/ActiveRecord.php
+++ b/framework/db/ar/ActiveRecord.php
@@ -101,9 +101,9 @@ abstract class ActiveRecord extends Model
 	 *    corresponding record.
 	 *  - an array of name-value pairs: it will be used to configure the [[ActiveQuery]] object.
 	 *
-	 * @return ActiveQuery|ActiveRecord|null the [[ActiveQuery]] instance for query purpose, or
+	 * @return ActiveQuery|ActiveRecord|boolean the [[ActiveQuery]] instance for query purpose, or
 	 * the ActiveRecord object when a scalar is passed to this method which is considered to be a
-	 * primary key value (null will be returned if no record is found in this case.)
+	 * primary key value (false will be returned if no record is found in this case.)
 	 */
 	public static function find($q = null)
 	{
diff --git a/framework/db/ar/ActiveRelation.php b/framework/db/ar/ActiveRelation.php
index 22986c1..f2cd7cf 100644
--- a/framework/db/ar/ActiveRelation.php
+++ b/framework/db/ar/ActiveRelation.php
@@ -19,22 +19,18 @@ namespace yii\db\ar;
  * @author Qiang Xue <qiang.xue@gmail.com>
  * @since 2.0
  */
-class ActiveRelation extends BaseActiveQuery
+class ActiveRelation extends ActiveQuery
 {
 	/**
-	 * @var string the class name of the ActiveRecord instances that this relation
-	 * should create and populate query results into
-	 */
-	public $modelClass;
-	/**
-	 * @var ActiveRecord the primary record that this relation is associated with.
+	 * @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 boolean whether this relation is a one-many relation
+	 * @var boolean whether this relation should populate all query results into AR instances.
+	 * If false, only the first row of the results will be taken.
 	 */
-	public $hasMany;
+	public $multiple;
 	/**
 	 * @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
@@ -47,78 +43,85 @@ class ActiveRelation extends BaseActiveQuery
 	 */
 	public $via;
 
-	public function one()
-	{
-		$models = $this->all();
-		return isset($models[0]) ? $models[0] : null;
-	}
-
-	public function all()
+	public function createCommand($db = null)
 	{
-		$models = array();
-		return $models;
+		if ($this->primaryModel !== null) {
+			$this->filterByPrimaryModels(array($this->primaryModel));
+		}
+		return parent::createCommand($db);
 	}
 
-	public function findWith($name, &$primaryRecords)
+	public function findWith($name, &$primaryModels)
 	{
 		if (empty($this->link) || !is_array($this->link)) {
 			throw new \yii\base\Exception('invalid link');
 		}
-		$this->addLinkCondition($primaryRecords);
-		$records = $this->find();
+		$this->filterByPrimaryModels($primaryModels);
 
-		/** @var array $map mapping key(s) to index of $primaryRecords */
-		$index = $this->buildRecordIndex($primaryRecords, array_values($this->link));
-		$this->initRecordRelation($primaryRecords, $name);
-		foreach ($records as $record) {
-			$key = $this->getRecordKey($record, array_keys($this->link));
-			if (isset($index[$key])) {
-				$primaryRecords[$map[$key]][$name] = $record;
+		if (count($primaryModels) === 1 && !$this->multiple) {
+			foreach ($primaryModels as $i => $primaryModel) {
+				$primaryModels[$i][$name] = $this->one();
+			}
+		} else {
+			$models = $this->all();
+			// distribute models into buckets which are indexed by the link keys
+			$buckets = array();
+			foreach ($models as $i => $model) {
+				$key = $this->getModelKey($model, array_keys($this->link));
+				if ($this->index !== null) {
+					$buckets[$key][$i] = $model;
+				} else {
+					$buckets[$key][] = $model;
+				}
+			}
+			if (!$this->multiple) {
+				foreach ($buckets as $i => $bucket) {
+					$buckets[$i] = reset($bucket);
+				}
+			}
+			foreach ($primaryModels as $i => $primaryModel) {
+				$key = $this->getModelKey($primaryModel, array_values($this->link));
+				if (isset($buckets[$key])) {
+					$primaryModels[$i][$name] = $buckets[$key];
+				} else {
+					$primaryModels[$i][$name] = $this->multiple ? array() : null;
+				}
 			}
 		}
 	}
 
-	protected function getRecordKey($record, $attributes)
+	protected function getModelKey($model, $attributes)
 	{
-		if (isset($attributes[1])) {
+		if (count($attributes) > 1) {
 			$key = array();
 			foreach ($attributes as $attribute) {
-				$key[] = is_array($record) ? $record[$attribute] : $record->$attribute;
+				$key[] = $model[$attribute];
 			}
 			return serialize($key);
 		} else {
-			$attribute = $attributes[0];
-			return is_array($record) ? $record[$attribute] : $record->$attribute;
-		}
-	}
-
-	protected function buildRecordIndex($records, $attributes)
-	{
-		$map = array();
-		foreach ($records as $i => $record) {
-			$map[$this->getRecordKey($record, $attributes)] = $i;
+			$attribute = reset($attributes);
+			return $model[$attribute];
 		}
-		return $map;
 	}
 
-	protected function addLinkCondition($primaryRecords)
+	protected function filterByPrimaryModels($primaryModels)
 	{
 		$attributes = array_keys($this->link);
 		$values = array();
 		if (isset($links[1])) {
 			// composite keys
-			foreach ($primaryRecords as $record) {
+			foreach ($primaryModels as $model) {
 				$v = array();
 				foreach ($this->link as $attribute => $link) {
-					$v[$attribute] = is_array($record) ? $record[$link] : $record->$link;
+					$v[$attribute] = is_array($model) ? $model[$link] : $model->$link;
 				}
 				$values[] = $v;
 			}
 		} else {
 			// single key
 			$attribute = $this->link[$links[0]];
-			foreach ($primaryRecords as $record) {
-				$values[] = is_array($record) ? $record[$attribute] : $record->$attribute;
+			foreach ($primaryModels as $model) {
+				$values[] = is_array($model) ? $model[$attribute] : $model->$attribute;
 			}
 		}
 		$this->andWhere(array('in', $attributes, $values));
diff --git a/framework/db/dao/BaseQuery.php b/framework/db/dao/BaseQuery.php
index aec115f..f91beb7 100644
--- a/framework/db/dao/BaseQuery.php
+++ b/framework/db/dao/BaseQuery.php
@@ -544,6 +544,7 @@ class BaseQuery extends \yii\base\Component
 			'where', 'limit', 'offset', 'orderBy', 'groupBy',
 			'join', 'having', 'union', 'params',
 		);
+		// todo: incorrect, do we need it? should we provide a configure() method instead?
 		foreach ($properties as $name => $value) {
 			if ($value !== null) {
 				$this->$name = $value;