yii\caching\DbDependency - Yii2 类参考手册

Class yii\caching\DbDependency

Inheritanceyii\caching\DbDependency » yii\caching\Dependency » yii\base\BaseObject
Implementsyii\base\Configurable
Available since version2.0

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

隐藏继承的属性 Hide inherited properties

属性Property类型 Type简介 Description定义在 Defined 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

隐藏继承的方法 Hide inherited methods

方法 Method简介 Description定义在 Defined By
__call() Calls the named method which is not a class method. yii\base\BaseObject
__construct() Constructor. yii\base\BaseObject
__get() Returns the value of an object property. yii\base\BaseObject
__isset() Checks if a property is set, i.e. defined and not null. yii\base\BaseObject
__set() Sets value of an object property. yii\base\BaseObject
__unset() Sets an object property to null. yii\base\BaseObject
canGetProperty() Returns a value indicating whether a property can be read. yii\base\BaseObject
canSetProperty() Returns a value indicating whether a property can be set. yii\base\BaseObject
className() Returns the fully qualified name of this class. yii\base\BaseObject
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\BaseObject
hasProperty() Returns a value indicating whether a property is defined. yii\base\BaseObject
init() Initializes the object. yii\base\BaseObject
isChanged() Checks whether the dependency is changed. yii\caching\Dependency
resetReusableData() Resets all cached data for reusable dependencies. yii\caching\Dependency

Protected Methods

隐藏继承的方法 Hide inherited methods

方法 Method简介 Description定义在 Defined 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

属性详情 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

方法详情 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