# Trait yii\db\QueryTrait

Implemented by | yii\db\ActiveQuery, yii\db\Query, yii\elasticsearch\ActiveQuery, yii\elasticsearch\Query, yii\mongodb\ActiveQuery, yii\mongodb\Query, yii\mongodb\file\ActiveQuery, yii\mongodb\file\Query, yii\redis\ActiveQuery, yii\sphinx\ActiveQuery, yii\sphinx\Query
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/db/QueryTrait.php

The BaseQuery trait represents the minimum method set of a database Query.

It is supposed to be used in a class that implements the yii\db\QueryInterface.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$emulateExecution | boolean | Whether to emulate the actual query execution, returning empty or false results. | yii\db\QueryTrait
$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
$orderBy | array | How to sort the query results. | yii\db\QueryTrait
$where | string|array|yii\db\ExpressionInterface | Query condition. | yii\db\QueryTrait

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
addOrderBy() | Adds additional ORDER BY columns to the query. | yii\db\QueryTrait
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
emulateExecution() | Sets whether to emulate query execution, preventing any interaction with data storage. | yii\db\QueryTrait
filterWhere() | Sets the WHERE part of the query but ignores empty operands. | yii\db\QueryTrait
indexBy() | Sets the indexBy() property. | yii\db\QueryTrait
limit() | Sets the LIMIT part of the query. | yii\db\QueryTrait
offset() | Sets the OFFSET part of the query. | yii\db\QueryTrait
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
where() | Sets the WHERE part of the query. | yii\db\QueryTrait

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
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

$emulateExecution public property (available since version 2.0.11)

Whether to emulate the actual query execution, returning empty or false results.

See also emulateExecution().

public boolean $emulateExecution = false
$indexBy public property

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 string|callable $indexBy = null
$limit public property

Maximum number of records to be returned. May be an instance of yii\db\ExpressionInterface. If not set or less than 0, it means no limit.

public integer|yii\db\ExpressionInterface $limit = null
$offset public property

Zero-based offset from where the records are to be returned. May be an instance of yii\db\ExpressionInterface. If not set or less than 0, it means starting from the beginning.

public integer|yii\db\ExpressionInterface $offset = null
$orderBy public property

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 or SORT_DESC. The array may also contain yii\db\ExpressionInterface objects. If that is the case, the expressions will be converted into strings without any change.

public array $orderBy = null
$where public property

Query condition. This refers to the WHERE clause in a SQL statement. For example, `['age' => 31, 'team' => 1]`.

See also where() for valid syntax on specifying this value.

public string|array|yii\db\ExpressionInterface $where = null

## Method Details

addOrderBy() public method

Adds additional ORDER BY columns to the query.

See also orderBy().

public $this addOrderBy ( $columns )

$columns

string|array|yii\db\ExpressionInterface

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).

Note that if your order-by is an expression containing commas, you should always use an array to represent the order-by information. Otherwise, the method will not be able to correctly determine the order-by columns.

Since version 2.0.7, an yii\db\ExpressionInterface object can be passed to specify the ORDER BY part explicitly in plain SQL.

return | $this | The query object itself

andFilterWhere() public method

Adds an additional WHERE condition to the existing one but ignores empty operands.

The new condition and the existing one will be joined using the 'AND' operator.

This method is similar to andWhere(). The main difference is that this method will remove empty query operands. As a result, this method is best suited for building query conditions based on filter values entered by users.

See also:

- filterWhere()
- orFilterWhere()

public $this andFilterWhere ( array $condition )
$condition | array | The new WHERE condition. Please refer to where() on how to specify this parameter.
return | $this | The query object itself

andWhere() public method

Adds an additional WHERE condition to the existing one.

The new condition and the existing one will be joined using the 'AND' operator.

See also:

- where()
- orWhere()

public $this andWhere ( $condition )
$condition | string|array|yii\db\ExpressionInterface | The new WHERE condition. Please refer to where() on how to specify this parameter.
return | $this | The query object itself

emulateExecution() public method (available since version 2.0.11)

Sets whether to emulate query execution, preventing any interaction with data storage.

After this mode is enabled, methods, returning query results like yii\db\QueryInterface::one(), yii\db\QueryInterface::all(), yii\db\QueryInterface::exists() and so on, will return empty or false values. You should use this method in case your program logic indicates query should not return any results, like in case you set false where condition like `0=1`.

public $this emulateExecution ( $value = true )
$value | boolean | Whether to prevent query execution.
return | $this | The query object itself.

filterCondition() protected method

Removes empty operands from the given query condition.

protected array filterCondition ( $condition )
$condition | array | The original condition
return | array | The condition with empty operands removed.
throws | yii\base\NotSupportedException | if the condition operator is not supported

filterWhere() public method

Sets the WHERE part of the query but ignores empty operands.

This method is similar to where(). The main difference is that this method will remove empty query operands. As a result, this method is best suited for building query conditions based on filter values entered by users.

The following code shows the difference between this method and where():

    // WHERE `age`=:age
    $query->filterWhere(['name' => null, 'age' => 20]);
    // WHERE `age`=:age
    $query->where(['age' => 20]);
    // WHERE `name` IS NULL AND `age`=:age
    $query->where(['name' => null, 'age' => 20]);

Note that unlike where(), you cannot pass binding parameters to this method.

See also:

- where()
- andFilterWhere()
- orFilterWhere()

public $this filterWhere ( array $condition )
$condition | array | The conditions that should be put in the WHERE part. See where() on how to specify this parameter.
return | $this | The query object itself

indexBy() public method

Sets the indexBy() property.

public $this indexBy ( $column )

$column

string|callable

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 | $this | The query object itself

isEmpty() protected method

Returns a value indicating whether the give value is "empty".

The value is considered "empty", if one of the following conditions is satisfied:

- it is `null`,
- an empty string (`''`),
- a string containing only whitespace characters,
- or an empty array.

protected boolean isEmpty ( $value )
$value | mixed |
return | boolean | If the value is empty

limit() public method

Sets the LIMIT part of the query.

public $this limit ( $limit )
$limit | integer|yii\db\ExpressionInterface|null | The limit. Use null or negative value to disable limit.
return | $this | The query object itself

normalizeOrderBy() protected method

Normalizes format of ORDER BY data.

protected array normalizeOrderBy ( $columns )
$columns | array|string|yii\db\ExpressionInterface | The columns value to normalize. See orderBy() and addOrderBy().

offset() public method

Sets the OFFSET part of the query.

public $this offset ( $offset )
$offset | integer|yii\db\ExpressionInterface|null | The offset. Use null or negative value to disable offset.
return | $this | The query object itself

orFilterWhere() public method

Adds an additional WHERE condition to the existing one but ignores empty operands.

The new condition and the existing one will be joined using the 'OR' operator.

This method is similar to orWhere(). The main difference is that this method will remove empty query operands. As a result, this method is best suited for building query conditions based on filter values entered by users.

See also:

- filterWhere()
- andFilterWhere()

public $this orFilterWhere ( array $condition )
$condition | array | The new WHERE condition. Please refer to where() on how to specify this parameter.
return | $this | The query object itself

orWhere() public method

Adds an additional WHERE condition to the existing one.

The new condition and the existing one will be joined using the 'OR' operator.

See also:

- where()
- andWhere()

public $this orWhere ( $condition )
$condition | string|array|yii\db\ExpressionInterface | The new WHERE condition. Please refer to where() on how to specify this parameter.
return | $this | The query object itself

orderBy() public method

Sets the ORDER BY part of the query.

See also addOrderBy().

public $this orderBy ( $columns )

$columns

string|array|yii\db\ExpressionInterface

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).

Note that if your order-by is an expression containing commas, you should always use an array to represent the order-by information. Otherwise, the method will not be able to correctly determine the order-by columns.

Since version 2.0.7, an yii\db\ExpressionInterface object can be passed to specify the ORDER BY part explicitly in plain SQL.

return | $this | The query object itself

where() public method

Sets the WHERE part of the query.

See yii\db\QueryInterface::where() for detailed documentation.

See also:

- andWhere()
- orWhere()

public $this where ( $condition )
$condition | string|array|yii\db\ExpressionInterface | The conditions that should be put in the WHERE part.
return | $this | The query object itself