Query.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         3.0.0
 * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\ORM;

use Cake\Database\Query as DatabaseQuery;
use Cake\Database\ValueBinder;
use Cake\Datasource\QueryTrait;
use Cake\ORM\EagerLoader;
use Cake\ORM\ResultSet;
use Cake\ORM\Table;
use JsonSerializable;

/**
 * Extends the base Query class to provide new methods related to association
 * loading, automatic fields selection, automatic type casting and to wrap results
 * into a specific iterator that will be responsible for hydrating results if
 * required.
 *
 */
class Query extends DatabaseQuery implements JsonSerializable {

	use QueryTrait {
		cache as private _cache;
		all as private _all;
		__call as private _call;
	}

/**
 * Indicates that the operation should append to the list
 *
 * @var int
 */
	const APPEND = 0;

/**
 * Indicates that the operation should prepend to the list
 *
 * @var int
 */
	const PREPEND = 1;

/**
 * Indicates that the operation should overwrite the list
 *
 * @var bool
 */
	const OVERWRITE = true;

/**
 * Whether the user select any fields before being executed, this is used
 * to determined if any fields should be automatically be selected.
 *
 * @var bool
 */
	protected $_hasFields;

/**
 * Tracks whether or not the original query should include
 * fields from the top level model.
 *
 * @var bool
 */
	protected $_autoFields;

/**
 * Boolean for tracking whether or not buffered results
 * are enabled.
 *
 * @var bool
 */
	protected $_useBufferedResults = true;

/**
 * Whether to hydrate results into entity objects
 *
 * @var bool
 */
	protected $_hydrate = true;

/**
 * A callable function that can be used to calculate the total amount of
 * records this query will match when not using `limit`
 *
 * @var callable
 */
	protected $_counter;

/**
 * Instance of a class responsible for storing association containments and
 * for eager loading them when this query is executed
 *
 * @var \Cake\ORM\EagerLoader
 */
	protected $_eagerLoader;

/**
 * Constuctor
 *
 * @param \Cake\Database\Connection $connection The connection object
 * @param \Cake\ORM\Table $table The table this query is starting on
 */
	public function __construct($connection, $table) {
		parent::__construct($connection);
		$this->repository($table);

		if ($this->_repository) {
			$this->addDefaultTypes($this->_repository);
		}
	}

/**
 * Hints this object to associate the correct types when casting conditions
 * for the database. This is done by extracting the field types from the schema
 * associated to the passed table object. This prevents the user from repeating
 * himself when specifying conditions.
 *
 * This method returns the same query object for chaining.
 *
 * @param \Cake\ORM\Table $table The table to pull types from
 * @return $this
 */
	public function addDefaultTypes(Table $table) {
		$alias = $table->alias();
		$schema = $table->schema();
		$fields = [];
		foreach ($schema->columns() as $f) {
			$fields[$f] = $fields[$alias . '.' . $f] = $schema->columnType($f);
		}
		$this->defaultTypes($fields);

		return $this;
	}

/**
 * Sets the instance of the eager loader class to use for loading associations
 * and storing containments. If called with no arguments, it will return the
 * currently configured instance.
 *
 * @param \Cake\ORM\EagerLoader $instance The eager loader to use. Pass null
 *   to get the current eagerloader.
 * @return \Cake\ORM\EagerLoader|$this
 */
	public function eagerLoader(EagerLoader $instance = null) {
		if ($instance === null) {
			if ($this->_eagerLoader === null) {
				$this->_eagerLoader = new EagerLoader;
			}
			return $this->_eagerLoader;
		}
		$this->_eagerLoader = $instance;
		return $this;
	}

/**
 * Sets the list of associations that should be eagerly loaded along with this
 * query. The list of associated tables passed must have been previously set as
 * associations using the Table API.
 *
 * ### Example:
 *
 * {{{
 *	// Bring articles' author information
 *	$query->contain('Author');
 *
 *	// Also bring the category and tags associated to each article
 *	$query->contain(['Category', 'Tag']);
 * }}}
 *
 * Associations can be arbitrarily nested using dot notation or nested arrays,
 * this allows this object to calculate joins or any additional queries that
 * must be executed to bring the required associated data.
 *
 * ### Example:
 *
 * {{{
 *	// Eager load the product info, and for each product load other 2 associations
 *	$query->contain(['Product' => ['Manufacturer', 'Distributor']);
 *
 *	// Which is equivalent to calling
 *	$query->contain(['Products.Manufactures', 'Products.Distributors']);
 *
 *	// For an author query, load his region, state and country
 *	$query->contain('Regions.States.Countries');
 * }}}
 *
 * It is possible to control the conditions and fields selected for each of the
 * contained associations:
 *
 * ### Example:
 *
 * {{{
 *	$query->contain(['Tags' => function($q) {
 *		return $q->where(['Tags.is_popular' => true]);
 *	}]);
 *
 *	$query->contain(['Products.Manufactures' => function($q) {
 *		return $q->select(['name'])->where(['Manufactures.active' => true]);
 *	}]);
 * }}}
 *
 * Each association might define special options when eager loaded, the allowed
 * options that can be set per association are:
 *
 * - foreignKey: Used to set a different field to match both tables, if set to false
 *   no join conditions will be generated automatically
 * - fields: An array with the fields that should be fetched from the association
 * - queryBuilder: Equivalent to passing a callable instead of an options array
 *
 * ### Example:
 *
 * {{{
 *  // Set options for the articles that will be eagerly loaded for an author
 *	$query->contain([
 *		'Articles' => [
 *			'fields' => ['title']
 *		]
 *	]);
 *
 *	// Use special join conditions for getting an article author's 'likes'
 *	$query->contain([
 *		'Likes' => [
 *			'foreignKey' => false,
 *			'queryBuilder' => function($q) {
 *				return $q->where(...); // Add full filtering conditions
 *			}
 *		]
 *	]);
 * }}}
 *
 * If called with no arguments, this function will return an array with
 * with the list of previously configured associations to be contained in the
 * result.
 *
 * If called with an empty first argument and $override is set to true, the
 * previous list will be emptied.
 *
 * @param array|string $associations list of table aliases to be queried
 * @param bool $override whether override previous list with the one passed
 * defaults to merging previous list with the new one.
 * @return array|$this
 */
	public function contain($associations = null, $override = false) {
		if (empty($associations) && $override) {
			$this->_eagerLoader = null;
		}

		$result = $this->eagerLoader()->contain($associations);
		if ($associations !== null || $override) {
			$this->_dirty();
		}
		if ($associations === null) {
			return $result;
		}

		return $this;
	}

/**
 * Adds filtering conditions to this query to only bring rows that have a relation
 * to another from an associated table, based on conditions in the associated table.
 *
 * This function will add entries in the `contain` graph.
 *
 * ### Example:
 *
 * {{{
 *  // Bring only articles that were tagged with 'cake'
 *	$query->matching('Tags', function($q) {
 *		return $q->where(['name' => 'cake']);
 *	);
 * }}}
 *
 * It is possible to filter by deep associations by using dot notation:
 *
 * ### Example:
 *
 * {{{
 *  // Bring only articles that were commented by 'markstory'
 *	$query->matching('Comments.Users', function($q) {
 *		return $q->where(['username' => 'markstory']);
 *	);
 * }}}
 *
 * As this function will create `INNER JOIN`, you might want to consider
 * calling `distinct` on this query as you might get duplicate rows if
 * your conditions don't filter them already. This might be the case, for example,
 * of the same user commenting more than once in the same article.
 *
 * ### Example:
 *
 * {{{
 *  // Bring unique articles that were commented by 'markstory'
 *	$query->distinct(['Articles.id'])
 *	->matching('Comments.Users', function($q) {
 *		return $q->where(['username' => 'markstory']);
 *	);
 * }}}
 *
 * Please note that the query passed to the closure will only accept calling
 * `select`, `where`, `andWhere` and `orWhere` on it. If you wish to
 * add more complex clauses you can do it directly in the main query.
 *
 * @param string $assoc The association to filter by
 * @param callable $builder a function that will receive a pre-made query object
 * that can be used to add custom conditions or selecting some fields
 * @return $this
 */
	public function matching($assoc, callable $builder = null) {
		$this->eagerLoader()->matching($assoc, $builder);
		$this->_dirty();
		return $this;
	}

/**
 * Enable/Disable buffered results.
 *
 * When enabled the ResultSet returned by this Query will be
 * buffered. This enables you to iterate a ResultSet multiple times, or
 * both cache and iterate the ResultSet.
 *
 * When disabled it will consume less memory as fetched results are not
 * remembered in the ResultSet.
 *
 * If called with no arguments, it will return whether or not buffering is
 * enabled.
 *
 * @param bool $enable whether or not to enable buffering
 * @return bool|$this
 */
	public function bufferResults($enable = null) {
		if ($enable === null) {
			return $this->_useBufferedResults;
		}

		$this->_dirty();
		$this->_useBufferedResults = (bool)$enable;
		return $this;
	}

/**
 * Returns a key => value array representing a single aliased field
 * that can be passed directly to the select() method.
 * The key will contain the alias and the value the actual field name.
 *
 * If the field is already aliased, then it will not be changed.
 * If no $alias is passed, the default table for this query will be used.
 *
 * @param string $field The field to alias
 * @param string $alias the alias used to prefix the field
 * @return array
 */
	public function aliasField($field, $alias = null) {
		$namespaced = strpos($field, '.') !== false;
		$aliasedField = $field;

		if ($namespaced) {
			list($alias, $field) = explode('.', $field);
		}

		if (!$alias) {
			$alias = $this->repository()->alias();
		}

		$key = sprintf('%s__%s', $alias, $field);
		if (!$namespaced) {
			$aliasedField = $alias . '.' . $field;
		}

		return [$key => $aliasedField];
	}

/**
 * Runs `aliasfield()` for each field in the provided list and returns
 * the result under a single array.
 *
 * @param array $fields The fields to alias
 * @param string $defaultAlias The default alias
 * @return array
 */
	public function aliasFields($fields, $defaultAlias = null) {
		$aliased = [];
		foreach ($fields as $alias => $field) {
			if (is_numeric($alias) && is_string($field)) {
				$aliased += $this->aliasField($field, $defaultAlias);
				continue;
			}
			$aliased[$alias] = $field;
		}

		return $aliased;
	}

/**
 * Populates or adds parts to current query clauses using an array.
 * This is handy for passing all query clauses at once. The option array accepts:
 *
 * - fields: Maps to the select method
 * - conditions: Maps to the where method
 * - limit: Maps to the limit method
 * - order: Maps to the order method
 * - offset: Maps to the offset method
 * - group: Maps to the group method
 * - having: Maps to the having method
 * - contain: Maps to the contain options for eager loading
 * - join: Maps to the join method
 * - page: Maps to the page method
 *
 * ## Example:
 *
 * {{{
 * $query->applyOptions([
 *   'fields' => ['id', 'name'],
 *   'conditions' => [
 *     'created >=' => '2013-01-01'
 *   ],
 *   'limit' => 10
 * ]);
 * }}}
 *
 * Is equivalent to:
 *
 * {{{
 *  $query
 *  ->select(['id', 'name'])
 *  ->where(['created >=' => '2013-01-01'])
 *  ->limit(10)
 * }}}
 *
 * @param array $options list of query clauses to apply new parts to.
 * @return $this
 */
	public function applyOptions(array $options) {
		$valid = [
			'fields' => 'select',
			'conditions' => 'where',
			'join' => 'join',
			'order' => 'order',
			'limit' => 'limit',
			'offset' => 'offset',
			'group' => 'group',
			'having' => 'having',
			'contain' => 'contain',
			'page' => 'page',
		];

		ksort($options);
		foreach ($options as $option => $values) {
			if (isset($valid[$option]) && isset($values)) {
				$this->{$valid[$option]}($values);
			} else {
				$this->_options[$option] = $values;
			}
		}

		return $this;
	}

/**
 * Returns the COUNT(*) for the query.
 *
 * @return int
 */
	public function count() {
		$query = clone $this;
		$query->limit(null);
		$query->order([], true);
		$query->offset(null);
		$query->mapReduce(null, null, true);
		$query->formatResults(null, true);
		$counter = $this->_counter;

		if ($counter) {
			$query->counter(null);
			return (int)$counter($query);
		}

		$count = ['count' => $query->func()->count('*')];
		if (!count($query->clause('group')) && !$query->clause('distinct')) {
			$statement = $query
				->select($count, true)
				->execute();
		} else {
			// Forcing at least one field to be selected
			$query->select(['_one_' => $query->newExpr()->add('1')]);
			$statement = $this->connection()->newQuery()
				->select($count)
				->from(['count_source' => $query])
				->execute();
		}

		$result = $statement->fetch('assoc')['count'];
		$statement->closeCursor();
		return (int)$result;
	}

/**
 * Registers a callable function that will be executed when the `count` method in
 * this query is called. The return value for the function will be set as the
 * return value of the `count` method.
 *
 * This is particularly useful when you need to optimize a query for returning the
 * count, for example removing unnecessary joins, removing group by or just return
 * an estimated number of rows.
 *
 * The callback will receive as first argument a clone of this query and not this
 * query itself.
 *
 * @param callable $counter The counter value
 * @return $this
 */
	public function counter($counter) {
		$this->_counter = $counter;
		return $this;
	}

/**
 * Toggle hydrating entites.
 *
 * If set to false array results will be returned
 *
 * @param bool|null $enable Use a boolean to set the hydration mode.
 *   Null will fetch the current hydration mode.
 * @return bool|$this A boolean when reading, and $this when setting the mode.
 */
	public function hydrate($enable = null) {
		if ($enable === null) {
			return $this->_hydrate;
		}

		$this->_dirty();
		$this->_hydrate = (bool)$enable;
		return $this;
	}

/**
 * {@inheritDoc}
 *
 * @return $this
 * @throws \RuntimeException When you attempt to cache a non-select query.
 */
	public function cache($key, $config = 'default') {
		if ($this->_type !== 'select' && $this->_type !== null) {
			throw new \RuntimeException('You cannot cache the results of non-select queries.');
		}
		return $this->_cache($key, $config);
	}

/**
 * {@inheritDoc}
 *
 * @throws \RuntimeException if this method is called on a non-select Query.
 */
	public function all() {
		if ($this->_type !== 'select' && $this->_type !== null) {
			throw new \RuntimeException(
				'You cannot call all() on a non-select query. Use execute() instead.'
			);
		}
		return $this->_all();
	}

/**
 * {@inheritDoc}
 */
	public function sql(ValueBinder $binder = null) {
		$this->_transformQuery();
		return parent::sql($binder);
	}

/**
 * {@inheritDoc}
 */
	public function execute() {
		$this->_transformQuery();
		return parent::execute();
	}

/**
 * Executes this query and returns a ResultSet object containing the results.
 * This will also setup the correct statement class in order to eager load deep
 * associations.
 *
 * @return \Cake\ORM\ResultSet
 */
	protected function _execute() {
		$statement = $this->eagerLoader()->loadExternal($this, $this->execute());
		return new ResultSet($this, $statement);
	}

/**
 * Applies some defaults to the query object before it is executed.
 *
 * Specifically add the FROM clause, adds default table fields if none are
 * specified and applies the joins required to eager load associations defined
 * using `contain`
 *
 * @see \Cake\Database\Query::execute()
 * @return $this
 */
	protected function _transformQuery() {
		if (!$this->_dirty) {
			return;
		}

		if ($this->_type === 'select') {
			if (empty($this->_parts['from'])) {
				$this->from([$this->_repository->alias() => $this->_repository->table()]);
			}
			$this->_addDefaultFields();
			$this->eagerLoader()->attachAssociations($this, $this->_repository, !$this->_hasFields);
		}
	}

/**
 * Inspects if there are any set fields for selecting, otherwise adds all
 * the fields for the default table.
 *
 * @return void
 */
	protected function _addDefaultFields() {
		$select = $this->clause('select');
		$this->_hasFields = true;

		if (!count($select) || $this->_autoFields === true) {
			$this->_hasFields = false;
			$this->select($this->repository()->schema()->columns());
			$select = $this->clause('select');
		}

		$aliased = $this->aliasFields($select, $this->repository()->alias());
		$this->select($aliased, true);
	}

/**
 * Apply custom finds to against an existing query object.
 *
 * Allows custom find methods to be combined and applied to each other.
 *
 * {{{
 * $table->find('all')->find('recent');
 * }}}
 *
 * The above is an example of stacking multiple finder methods onto
 * a single query.
 *
 * @param string $finder The finder method to use.
 * @param array $options The options for the finder.
 * @return $this Returns a modified query.
 * @see \Cake\ORM\Table::find()
 */
	public function find($finder, array $options = []) {
		return $this->repository()->callFinder($finder, $this, $options);
	}

/**
 * Marks a query as dirty, removing any preprocessed information
 * from in memory caching such as previous results
 *
 * @return void
 */
	protected function _dirty() {
		$this->_results = null;
		parent::_dirty();
	}

/**
 * Create an update query.
 *
 * This changes the query type to be 'update'.
 * Can be combined with set() and where() methods to create update queries.
 *
 * @param string $table Unused parameter.
 * @return $this
 */
	public function update($table = null) {
		$table = $this->repository()->table();
		return parent::update($table);
	}

/**
 * Create a delete query.
 *
 * This changes the query type to be 'delete'.
 * Can be combined with the where() method to create delete queries.
 *
 * @param string $table Unused parameter.
 * @return $this
 */
	public function delete($table = null) {
		$repo = $this->repository();
		$this->from([$repo->alias() => $repo->table()]);
		return parent::delete();
	}

/**
 * Create an insert query.
 *
 * This changes the query type to be 'insert'.
 * Note calling this method will reset any data previously set
 * with Query::values()
 *
 * Can be combined with the where() method to create delete queries.
 *
 * @param array $columns The columns to insert into.
 * @param array $types A map between columns & their datatypes.
 * @return $this
 */
	public function insert(array $columns, array $types = []) {
		$table = $this->repository()->table();
		$this->into($table);
		return parent::insert($columns, $types);
	}

/**
 * {@inheritDoc}
 *
 * @throws \BadMethodCallException if the method is called for a non-select query
 */
	public function __call($method, $arguments) {
		if ($this->type() === 'select') {
			return $this->_call($method, $arguments);
		}

		throw new \BadMethodCallException(
			sprintf('Cannot call method "%s" on a "%s" query', $method, $this->type())
		);
	}

/**
 * {@inheritDoc}
 */
	public function __debugInfo() {
		return parent::__debugInfo() + [
			'hydrate' => $this->_hydrate,
			'buffered' => $this->_useBufferedResults,
			'formatters' => count($this->_formatters),
			'mapReducers' => count($this->_mapReduce),
			'contain' => $this->contain(),
			'extraOptions' => $this->_options,
			'repository' => $this->_repository
		];
	}

/**
 * Executes the query and converts the result set into JSON.
 *
 * Part of JsonSerializable interface.
 *
 * @return \Cake\ORM\ResultSet The data to convert to JSON.
 */
	public function jsonSerialize() {
		return $this->all();
	}

/**
 * Get/Set whether or not the ORM should automatically append fields.
 *
 * By default calling select() will disable auto-fields. You can re-enable
 * auto-fields with this method.
 *
 * @param bool $value The value to set or null to read the current value.
 * @return bool|$this Either the current value or the query object.
 */
	public function autoFields($value = null) {
		if ($value === null) {
			return $this->_autoFields;
		}
		$this->_autoFields = (bool)$value;
		return $this;
	}

}