refactored ActiveRecord classes to use Interfaces and traits

this allows us to implement other activerecord implementations based on
NoSQL dbms

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,
+	'id' => SORT_ASC,
-	'name' => Query::SORT_DESC,
+	'name' => SORT_DESC,
 ]);
 ```
 

framework/yii/ar/ActiveQueryInterface.php

@@ -0,0 +1,59 @@
+<?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 relation 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);
+
+	/**
+	 * 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

@@ -10,10 +10,7 @@ namespace yii\ar;
 use yii\db\ActiveRecord;
 
 /**
- * ActiveQuery represents a DB query associated with an Active Record class.
+ * ActiveQueryTrait implements the common set of methods that are used by DB queries associated with an Active Record class.
- *
- * ActiveQuery instances are usually created by [[ActiveRecord::find()]], [[ActiveRecord::findBySql()]]
- * and [[ActiveRecord::count()]].
  *
  * ActiveQuery mainly provides the following methods to retrieve the query results:
  *
@@ -150,6 +147,11 @@ trait ActiveQueryTrait
 		return parent::indexBy($column);
 	}
 
+	/**
+	 * Converts found rows into model instances
+	 * @param array $rows
+	 * @return array|ActiveRecord[]
+	 */
 	private function createModels($rows)
 	{
 		$models = [];
@@ -187,6 +189,10 @@ trait ActiveQueryTrait
 		return $models;
 	}
 
+	/**
+	 * @param ActiveRecord[] $models
+	 * @param array $with
+	 */
 	private function populateRelations(&$models, $with)
 	{
 		$primaryModel = new $this->modelClass;
@@ -203,7 +209,7 @@ trait ActiveQueryTrait
 	/**
 	 * @param ActiveRecord $model
 	 * @param array $with
-	 * @return ActiveRelation[]
+	 * @return ActiveRelationInterface[]
 	 */
 	private function normalizeRelations($model, $with)
 	{

framework/yii/ar/ActiveRelationInterface.php

@@ -0,0 +1,36 @@
+<?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.
+ *
+ * @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);
+
+	/**
+	 * 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 $primaryModels primary models
+	 * @return array the related models
+	 */
+	public function findWith($name, &$primaryModels);
+}

framework/yii/ar/ActiveRelationTrait.php

@@ -23,6 +23,7 @@ use yii\db\ActiveRecord;
  * If a relation involves a pivot table, it may be specified by [[via()]] or [[viaTable()]] method.
  *
  * @author Qiang Xue <qiang.xue@gmail.com>
+ * @author Carsten Brandt <mail@cebe.cc>
  * @since 2.0
  */
 trait ActiveRelationTrait

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) {
+		if (!$this->query instanceof QueryInterface) {
-			throw new InvalidConfigException('The "query" property must be an instance of Query or its subclass.');
+			throw new InvalidConfigException('The "query" property must be an instance of a class that implements the QueryInterface e.g. yii\db\Query or its subclasses.');
 		}
 		if (($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) {
+		if (!$this->query instanceof QueryInterface) {
-			throw new InvalidConfigException('The "query" property must be an instance of Query or its subclass.');
+			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) $query->limit(-1)->offset(-1)->count($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()]]
+ * ActiveQuery instances are usually created by [[ActiveRecord::find()]] and [[ActiveRecord::findBySql()]].
- * and [[ActiveRecord::count()]].
  *
  * ActiveQuery mainly provides the following methods to retrieve the query results:
  *
@@ -42,11 +43,12 @@ 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
 {
-	use \yii\ar\ActiveQueryTrait;
+	use ActiveQueryTrait;
 
 	/**
 	 * @var string the SQL statement to be executed for retrieving AR records.

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
@@ -95,10 +97,6 @@ class ActiveRecord extends Model
 	const OP_ALL = 0x07;
 
 	/**
-	 * @var string the name of the class to use for relations.
-	 */
-	protected $relationClassName = 'yii\\db\\ActiveRelation';
-	/**
 	 * @var array attribute values indexed by attribute names
 	 */
 	private $_attributes = [];
@@ -256,7 +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.
@@ -389,7 +387,7 @@ class ActiveRecord extends Model
 				return $this->_related[$name];
 			}
 			$value = parent::__get($name);
-			if ($value instanceof $this->relationClassName) {
+			if ($value instanceof ActiveRelationInterface) {
 				return $this->_related[$name] = $value->multiple ? $value->all() : $value->one();
 			} else {
 				return $value;
@@ -478,7 +476,7 @@ class ActiveRecord extends Model
 	 */
 	public function hasOne($class, $link)
 	{
-		return new $this->relationClassName([
+		return $this->createActiveRelation([
 			'modelClass' => $class,
 			'primaryModel' => $this,
 			'link' => $link,
@@ -516,7 +514,7 @@ class ActiveRecord extends Model
 	 */
 	public function hasMany($class, $link)
 	{
-		return new $this->relationClassName([
+		return $this->createActiveRelation([
 			'modelClass' => $class,
 			'primaryModel' => $this,
 			'link' => $link,
@@ -525,6 +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)
@@ -1287,7 +1297,7 @@ class ActiveRecord extends Model
 		$getter = 'get' . $name;
 		try {
 			$relation = $this->$getter();
-			if ($relation instanceof $this->relationClassName) {
+			if ($relation instanceof ActiveRelationInterface) {
 				return $relation;
 			} else {
 				return null;

framework/yii/db/ActiveRelation.php

@@ -7,6 +7,8 @@
  */
 
 namespace yii\db;
+use yii\ar\ActiveRelationInterface;
+use yii\ar\ActiveRelationTrait;
 
 /**
  * ActiveRelation represents a relation between two Active Record classes.
@@ -24,17 +26,12 @@ namespace yii\db;
  * 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
 {
-	use \yii\ar\ActiveRelationTrait;
+	use ActiveRelationTrait;
-
-	/**
-	 * @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;
 
 	/**
 	 * Specifies the pivot table.

framework/yii/db/Query.php

@@ -33,24 +33,14 @@ 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
 {
 	use QueryTrait;
 
 	/**
-	 * Sort ascending
-	 * @see orderBy()
-	 */
-	const SORT_ASC = false;
-	/**
-	 * Sort descending
-	 * @see orderBy()
-	 */
-	const SORT_DESC = true;
-
-	/**
 	 * @var array the columns being selected. For example, `['id', 'name']`.
 	 * This is used to construct the SELECT clause in a SQL statement. If not set, if means selecting all columns.
 	 * @see select()
@@ -189,13 +179,13 @@ class Query extends Component
 
 	/**
 	 * Returns the number of records.
+	 * @param Connection $db the database connection used to generate the SQL statement.
+	 * If this parameter is not given (or null), the `db` application component will be used.
 	 * @param string $q the COUNT expression. Defaults to '*'.
 	 * Make sure you properly quote column names in the expression.
-	 * @param Connection $db the database connection used to generate the SQL statement.
-	 * If this parameter is not given, the `db` application component will be used.
 	 * @return integer number of records
 	 */
-	public function count($q = '*', $db = null)
+	public function count($db = null, $q = '*')
 	{
 		$this->select = ["COUNT($q)"];
 		return $this->createCommand($db)->queryScalar();

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

@@ -0,0 +1,205 @@
+<?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 Connection $db the database connection used to execute the query.
+	 * If this parameter is not given, the `db` application component will be used.
+	 * @return integer number of records
+	 */
+	public function count($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);
+}

framework/yii/db/QueryTrait.php

@@ -7,18 +7,6 @@
 
 namespace yii\db;
 
-// TODO where to put these constants?
-/**
- * Sort ascending
- * @see orderBy
- */
-const SORT_ASC = false;
-/**
- * Sort descending
- * @see orderBy
- */
-const SORT_DESC = true;
-
 /**
  * The BaseQuery trait represents the minimum method set of a database Query.
  *
@@ -53,8 +41,10 @@ trait QueryTrait
 	/**
 	 * @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.
+	 * can be either [SORT_ASC](http://php.net/manual/en/array.constants.php#constant.sort-asc)
-	 * If that is the case, the expressions will be converted into strings without any change.
+	 * 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;
 	/**
@@ -86,90 +76,9 @@ trait QueryTrait
 	}
 
 	/**
-	 * Executes the query and returns all results as an array.
-	 * @return array the query results. If the query results in nothing, an empty array will be returned.
-	 */
-	abstract public function all();
-
-	/**
-	 * Executes the query and returns a single row of result.
-	 * @return array|boolean the first row (in terms of an array) of the query result. False is returned if the query
-	 * results in nothing.
-	 */
-	abstract public function one();
-
-	/**
-	 * Returns the number of records.
-	 * @return integer number of records
-	 */
-	abstract public function count();
-
-	/**
-	 * Returns a value indicating whether the query result contains any row of data.
-	 * @return boolean whether the query result contains any row of data.
-	 */
-	abstract public function exists();
-
-	/**
 	 * Sets the WHERE part of the query.
 	 *
-	 * The method requires a $condition parameter.
+	 * See [[QueryInterface::where()]] for detailed documentation.
-	 *
-	 * 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
@@ -224,7 +133,7 @@ trait QueryTrait
 	 * 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]`).
+	 * (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
@@ -240,7 +149,7 @@ trait QueryTrait
 	 * 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]`).
+	 * (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
@@ -266,9 +175,9 @@ trait QueryTrait
 			$result = [];
 			foreach ($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;
+					$result[$matches[1]] = strcasecmp($matches[2], 'desc') ? SORT_ASC : SORT_DESC;
 				} else {
-					$result[$column] = self::SORT_ASC;
+					$result[$column] = SORT_ASC;
 				}
 			}
 			return $result;