Class yii\caching\DbDependency

继承yii\caching\DbDependency » yii\caching\Dependency » yii\base\BaseObject
实现yii\base\Configurable
可用自版本2.0
源代码 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.

公共属性

隐藏继承的属性

属性类型描述定义在
$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

公共方法

隐藏继承的方法

方法描述定义在
__call() 调用不是类方法的已命名方法. yii\base\BaseObject
__construct() 构造函数. yii\base\BaseObject
__get() 返回对象属性的值. yii\base\BaseObject
__isset() 检查属性是否已设置, 即已定义且不为null. yii\base\BaseObject
__set() 设置对象属性的值. yii\base\BaseObject
__unset() 将对象属性设置为null. yii\base\BaseObject
canGetProperty() 返回一个值, 指示属性是否可读. yii\base\BaseObject
canSetProperty() 返回一个值, 指示属性是否可写. yii\base\BaseObject
className() 返回此类的完全限定名称. 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() 返回一个值, 指示方法是否已定义. yii\base\BaseObject
hasProperty() 返回一个值, 指示属性是否已定义. yii\base\BaseObject
init() 初始化对象. yii\base\BaseObject
isChanged() Checks whether the dependency is changed. yii\caching\Dependency
resetReusableData() Resets all cached data for reusable dependencies. yii\caching\Dependency

受保护的方法

隐藏继承的方法

方法描述定义在
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

$db public 属性

The application component ID of the DB connection.

public string $db 'db'
$params public 属性

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

public array $params = []
$sql public 属性

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

generateDependencyData() protected 方法

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