Class yii\caching\DbDependency
| Inheritance | yii\caching\DbDependency » yii\caching\Dependency » yii\base\BaseObject |
|---|---|
| Implements | yii\base\Configurable |
| Available since version | 2.0 |
| 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
| Property | Type | Description | 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
| Method | Description | 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
| Method | Description | 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 |
Property Details
The application component ID of the DB connection.
The parameters (name => value) to be bound to the SQL statement specified by $sql.
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.
Method Details
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 |