# Class yii\mongodb\Query

Inheritance | yii\mongodb\Query » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable, yii\db\QueryInterface
Uses Traits | yii\db\QueryTrait
Subclasses | yii\mongodb\ActiveQuery, yii\mongodb\file\ActiveQuery, yii\mongodb\file\Query
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2-mongodb/blob/master/Query.php

Query represents Mongo "find" operation.

Query provides a set of methods to facilitate the specification of "find" command. These methods can be chained together.

For example,

    $query = new Query();
    // compose the query
    $query->select(['name', 'status'])
        ->from('customer')
        ->limit(10);
    // execute the query
    $rows = $query->all();

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$collection | yii\mongodb\Collection | Collection instance. This property is read-only. | yii\mongodb\Query
$emulateExecution | boolean | Whether to emulate the actual query execution, returning empty or false results. | yii\db\QueryTrait
$from | string|array | The collection to be selected from. | yii\mongodb\Query
$indexBy | string|callable | The name of the column by which the query results should be indexed by. | yii\db\QueryTrait
$limit | integer|yii\db\ExpressionInterface | Maximum number of records to be returned. | yii\db\QueryTrait
$offset | integer|yii\db\ExpressionInterface | Zero-based offset from where the records are to be returned. | yii\db\QueryTrait
$options | array | Cursor options in format: optionKey => optionValue | yii\mongodb\Query
$orderBy | array | How to sort the query results. | yii\db\QueryTrait
$select | array | The fields of the results to return. | yii\mongodb\Query
$where | string|array|yii\db\ExpressionInterface | Query condition. | yii\db\QueryTrait

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
addOptions() | Adds additional cursor options. | yii\mongodb\Query
addOrderBy() | Adds additional ORDER BY columns to the query. | yii\db\QueryTrait
all() | Executes the query and returns all results as an array. | yii\mongodb\Query
andFilterCompare() | Helper method for easy querying on values containing some common operators. | yii\mongodb\Query
andFilterWhere() | Adds an additional WHERE condition to the existing one but ignores empty operands. | yii\db\QueryTrait
andWhere() | Adds an additional WHERE condition to the existing one. | yii\db\QueryTrait
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
average() | Returns the average of the specified column values. | yii\mongodb\Query
batch() | Starts a batch query. | yii\mongodb\Query
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
buildCursor() | Builds the MongoDB cursor for this query. | yii\mongodb\Query
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
column() | Executes the query and returns the first column of the result. | yii\mongodb\Query
count() | Returns the number of records. | yii\mongodb\Query
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
distinct() | Returns a list of distinct values for the given column across a collection. | yii\mongodb\Query
each() | Starts a batch query and retrieves data row by row. | yii\mongodb\Query
emulateExecution() | Sets whether to emulate query execution, preventing any interaction with data storage. | yii\db\QueryTrait
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
exists() | Returns a value indicating whether the query result contains any row of data. | yii\mongodb\Query
filterWhere() | Sets the WHERE part of the query but ignores empty operands. | yii\db\QueryTrait
from() | Sets the collection to be selected from. | yii\mongodb\Query
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getCollection() | Returns the Mongo collection for this query. | yii\mongodb\Query
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
indexBy() | Sets the indexBy() property. | yii\db\QueryTrait
init() | Initializes the object. | yii\base\BaseObject
limit() | Sets the LIMIT part of the query. | yii\db\QueryTrait
max() | Returns the maximum of the specified column values. | yii\mongodb\Query
min() | Returns the minimum of the specified column values. | yii\mongodb\Query
modify() | Performs 'findAndModify' query and returns a single row of result. | yii\mongodb\Query
off() | Detaches an existing event handler from this component. | yii\base\Component
offset() | Sets the OFFSET part of the query. | yii\db\QueryTrait
on() | Attaches an event handler to an event. | yii\base\Component
one() | Executes the query and returns a single row of result. | yii\mongodb\Query
options() | Sets the cursor options. | yii\mongodb\Query
orFilterWhere() | Adds an additional WHERE condition to the existing one but ignores empty operands. | yii\db\QueryTrait
orWhere() | Adds an additional WHERE condition to the existing one. | yii\db\QueryTrait
orderBy() | Sets the ORDER BY part of the query. | yii\db\QueryTrait
populate() | Converts the raw query results into the format as specified by this query. | yii\mongodb\Query
prepare() | Prepares for query building. | yii\mongodb\Query
scalar() | Returns the query result as a scalar value. | yii\mongodb\Query
select() | Sets the list of fields of the results to return. | yii\mongodb\Query
sum() | Returns the sum of the specified column values. | yii\mongodb\Query
trigger() | Triggers an event. | yii\base\Component
where() | Sets the WHERE part of the query. | yii\db\QueryTrait

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
aggregate() | Performs the aggregation for the given column. | yii\mongodb\Query
fetchRows() | Fetches rows from the given Mongo cursor. | yii\mongodb\Query
fetchRowsInternal() |  | yii\mongodb\Query
filterCondition() | Removes empty operands from the given query condition. | yii\db\QueryTrait
isEmpty() | Returns a value indicating whether the give value is "empty". | yii\db\QueryTrait
normalizeOrderBy() | Normalizes format of ORDER BY data. | yii\db\QueryTrait

## Property Details

$collection public property

Collection instance. This property is read-only.

public yii\mongodb\Collection $collection = null
$from public property

The collection to be selected from. If string considered as the name of the collection inside the default database. If array - first element considered as the name of the database, second - as name of collection inside that database

See also from().

public string|array $from = null
$options public property

Cursor options in format: optionKey => optionValue

See also:

- \MongoDB\Driver\Cursor::addOption()
- options()

public array $options = []
$select public property

The fields of the results to return. For example: `['name', 'group_id']`, `['name' => true, '_id' => false]`. Unless directly excluded, the "_id" field is always returned. If not set, it means selecting all columns.

See also select().

public array $select = []

## Method Details

addOptions() public method

Adds additional cursor options.

See also options().

public $this addOptions ( $options )
$options | array | Cursor options in format: optionName => optionValue
return | $this | The query object itself

aggregate() protected method

Performs the aggregation for the given column.

protected integer aggregate ( $column, $operator, $db )
$column | string | Column name.
$operator | string | Aggregation operator.
$db | yii\mongodb\Connection | The database connection used to execute the query.
return | integer | Aggregation result.

all() public method

Executes the query and returns all results as an array.

public array all ( $db = null )
$db | yii\mongodb\Connection | The Mongo connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | array | The query results. If the query results in nothing, an empty array will be returned.

andFilterCompare() public method (available since version 2.0.5)

Helper method for easy querying on values containing some common operators.

The comparison operator is intelligently determined based on the first few characters in the given value and internally translated to a MongoDB operator. In particular, it recognizes the following operators if they appear as the leading characters in the given value: <: the column must be less than the given value ($lt). >: the column must be greater than the given value ($gt). <=: the column must be less than or equal to the given value ($lte). >=: the column must be greater than or equal to the given value ($gte). <>: the column must not be the same as the given value ($ne). Note that when $partialMatch is true, this would mean the value must not be a substring of the column. =: the column must be equal to the given value ($eq). none of the above: use the $defaultOperator

Note that when the value is empty, no comparison expression will be added to the search condition.

See also Collection::buildCondition().

public $this andFilterCompare ( $name, $value, $defaultOperator = '=' )
$name | string | Column name
$value | string | Column value
$defaultOperator | string | Defaults to =, performing an exact match. For example: use 'LIKE' or 'REGEX' for partial cq regex matching
return | $this | The query object itself.

average() public method

Returns the average of the specified column values.

public integer average ( $q, $db = null )
$q | string | The column name. Make sure you properly quote column names in the expression.
$db | yii\mongodb\Connection | The Mongo connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | integer | The average of the specified column values.

batch() public method (available since version 2.1)

Starts a batch query.

A batch query supports fetching data in batches, which can keep the memory usage under a limit. This method will return a yii\mongodb\BatchQueryResult object which implements the `Iterator` interface and can be traversed to retrieve the data in batches.

For example,

    $query = (new Query)->from('user');
    foreach ($query->batch() as $rows) {
        // $rows is an array of 10 or fewer rows from user collection
    }

public yii\mongodb\BatchQueryResult batch ( $batchSize = 100, $db = null )
$batchSize | integer | The number of records to be fetched in each batch.
$db | yii\mongodb\Connection | The MongoDB connection. If not set, the "mongodb" application component will be used.
return | yii\mongodb\BatchQueryResult | The batch query result. It implements the `Iterator` interface and can be traversed to retrieve the data in batches.

buildCursor() public method

Builds the MongoDB cursor for this query.

public \MongoDB\Driver\Cursor buildCursor ( $db = null )
$db | yii\mongodb\Connection | The MongoDB connection used to execute the query.
return | \MongoDB\Driver\Cursor | Mongo cursor instance.

column() public method (available since version 2.1.2)

Executes the query and returns the first column of the result.

Column `_id` will be automatically excluded from select fields, if select() is not empty and `_id` is not selected explicitly.

public array column ( $db = null )
$db | yii\mongodb\Connection | The MongoDB connection used to generate the query. If this parameter is not given, the `mongodb` application component will be used.
return | array | The first column of the query result. An empty array is returned if the query results in nothing.

count() public method

Returns the number of records.

public integer count ( $q = '*', $db = null )
$q | string | Kept to match yii\db\QueryInterface, its value is ignored.
$db | yii\mongodb\Connection | The Mongo connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | integer | Number of records
throws | yii\mongodb\Exception | on failure.

distinct() public method

Returns a list of distinct values for the given column across a collection.

public array distinct ( $q, $db = null )
$q | string | Column to use.
$db | yii\mongodb\Connection | The MongoDB connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | array | Array of distinct values

each() public method (available since version 2.1)

Starts a batch query and retrieves data row by row.

This method is similar to batch() except that in each iteration of the result, only one row of data is returned. For example,

    $query = (new Query)->from('user');
    foreach ($query->each() as $row) {
    }

public yii\mongodb\BatchQueryResult each ( $batchSize = 100, $db = null )
$batchSize | integer | The number of records to be fetched in each batch.
$db | yii\mongodb\Connection | The MongoDB connection. If not set, the "mongodb" application component will be used.
return | yii\mongodb\BatchQueryResult | The batch query result. It implements the `Iterator` interface and can be traversed to retrieve the data in batches.

exists() public method

Returns a value indicating whether the query result contains any row of data.

public boolean exists ( $db = null )
$db | yii\mongodb\Connection | The Mongo connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | boolean | Whether the query result contains any row of data.

fetchRows() protected method

Fetches rows from the given Mongo cursor.

protected array|boolean fetchRows ( $cursor, $all = true, $indexBy = null )
$cursor | \MongoDB\Driver\Cursor | Mongo cursor instance to fetch data from.
$all | boolean | Whether to fetch all rows or only first one.
$indexBy | string|callable | The column name or PHP callback, by which the query results should be indexed by.
return | array|boolean | Result.
throws | yii\mongodb\Exception | on failure.

fetchRowsInternal() protected method

See also yii\mongodb\Query::fetchRows().

protected array|boolean fetchRowsInternal ( $cursor, $all )
$cursor | \MongoDB\Driver\Cursor | Mongo cursor instance to fetch data from.
$all | boolean | Whether to fetch all rows or only first one.
return | array|boolean | Result.

from() public method

Sets the collection to be selected from.

public $this from ( $collection )
$collection |  |
return | $this | The query object itself.

getCollection() public method

Returns the Mongo collection for this query.

public yii\mongodb\Collection getCollection ( $db = null )
$db | yii\mongodb\Connection | Mongo connection.
return | yii\mongodb\Collection | Collection instance.

max() public method

Returns the maximum of the specified column values.

public integer max ( $q, $db = null )
$q | string | The column name. Make sure you properly quote column names in the expression.
$db | yii\mongodb\Connection | The MongoDB connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | integer | The maximum of the specified column values.

min() public method

Returns the minimum of the specified column values.

public integer min ( $q, $db = null )
$q | string | The column name. Make sure you properly quote column names in the expression.
$db | yii\mongodb\Connection | The MongoDB connection used to execute the query. If this parameter is not given, the `db` application component will be used.
return | integer | The minimum of the specified column values.

modify() public method

Performs 'findAndModify' query and returns a single row of result.

public array|null modify ( $update, $options = [], $db = null )
$update | array | Update criteria
$options | array | List of options in format: optionName => optionValue.
$db | yii\mongodb\Connection | The Mongo connection used to execute the query.
return | array|null | The original document, or the modified document when $options['new'] is set.

one() public method

Executes the query and returns a single row of result.

public array|false one ( $db = null )
$db | yii\mongodb\Connection | The Mongo connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | array|false | The first row (in terms of an array) of the query result. `false` is returned if the query results in nothing.

options() public method

Sets the cursor options.

See also addOptions().

public $this options ( $options )
$options | array | Cursor options in format: optionName => optionValue
return | $this | The query object itself

populate() public method

Converts the raw query results into the format as specified by this query.

This method is internally used to convert the data fetched from database into the format as required by this query.

public array populate ( $rows )
$rows | array | The raw query result from database
return | array | The converted query result

prepare() public method (available since version 2.1.3)

Prepares for query building.

This method is called before actual query composition, e.g. building cursor, count etc. You may override this method to do some final preparation work before query execution.

public $this prepare ( )
return | $this | A prepared query instance.

scalar() public method (available since version 2.1.2)

Returns the query result as a scalar value.

The value returned will be the first column in the first row of the query results. Column `_id` will be automatically excluded from select fields, if select() is not empty and `_id` is not selected explicitly.

public string|null|false scalar ( $db = null )
$db | yii\mongodb\Connection | The MongoDB connection used to generate the query. If this parameter is not given, the `mongodb` application component will be used.
return | string|null|false | The value of the first column in the first row of the query result. `false` is returned if the query result is empty.

select() public method

Sets the list of fields of the results to return.

public $this select ( array $fields )
$fields | array | Fields of the results to return.
return | $this | The query object itself.

sum() public method

Returns the sum of the specified column values.

public integer sum ( $q, $db = null )
$q | string | The column name. Make sure you properly quote column names in the expression.
$db | yii\mongodb\Connection | The Mongo connection used to execute the query. If this parameter is not given, the `mongodb` application component will be used.
return | integer | The sum of the specified column values