Class yii\caching\DbDependency

Inheritanceyii\caching\DbDependency » yii\caching\Dependency » yii\base\Object
Implementsyii\base\Configurable
Available since version2.0
Source Code https://github.com/yiisoft/yii2/blob/master/framework/caching/DbDependency.php

DbDependency represents a dependency based on the query result of a SQL statement.

If the query result changes, the dependency is considered as changed. The query is specified via the $sql property.

For more details and usage information on Cache, see the guide article on caching.

Public Properties

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PropertyTypeDescriptionDefined By
$data mixed The dependency data that is saved in cache and later is compared with the latest dependency data. yii\caching\Dependency
$db string The application component ID of the DB connection. yii\caching\DbDependency
$params array The parameters (name => value) to be bound to the SQL statement specified by $sql. yii\caching\DbDependency
$reusable boolean Whether this dependency is reusable or not. yii\caching\Dependency
$sql string The SQL query whose result is used to determine if the dependency has been changed. yii\caching\DbDependency

Public Methods

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MethodDescriptionDefined By
__call() Calls the named method which is not a class method. yii\base\Object
__construct() Constructor. yii\base\Object
__get() Returns the value of an object property. yii\base\Object
__isset() Checks if a property is set, i.e. defined and not null. yii\base\Object
__set() Sets value of an object property. yii\base\Object
__unset() Sets an object property to null. yii\base\Object
canGetProperty() Returns a value indicating whether a property can be read. yii\base\Object
canSetProperty() Returns a value indicating whether a property can be set. yii\base\Object
className() Returns the fully qualified name of this class. yii\base\Object
evaluateDependency() Evaluates the dependency by generating and saving the data related with dependency. yii\caching\Dependency
getHasChanged() Returns a value indicating whether the dependency has changed. yii\caching\Dependency
hasMethod() Returns a value indicating whether a method is defined. yii\base\Object
hasProperty() Returns a value indicating whether a property is defined. yii\base\Object
init() Initializes the object. yii\base\Object
isChanged() Checks whether the dependency is changed yii\caching\Dependency
resetReusableData() Resets all cached data for reusable dependencies. yii\caching\Dependency

Protected Methods

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MethodDescriptionDefined By
generateDependencyData() Generates the data needed to determine if dependency has been changed. yii\caching\DbDependency
generateReusableHash() Generates a unique hash that can be used for retrieving reusable dependency data. yii\caching\Dependency

Property Details

$db public property

The application component ID of the DB connection.

public string $db 'db'
$params public property

The parameters (name => value) to be bound to the SQL statement specified by $sql.

public array $params = []
$sql public property

The SQL query whose result is used to determine if the dependency has been changed. Only the first row of the query result will be used.

public string $sql null

Method Details

generateDependencyData() protected method

Generates the data needed to determine if dependency has been changed.

This method returns the value of the global state.

protected mixed generateDependencyData ( $cache )
$cache yii\caching\CacheInterface

The cache component that is currently evaluating this dependency

return mixed

The data needed to determine if dependency has been changed.

throws yii\base\InvalidConfigException

if $db is not a valid application component ID