CDbExpression
| 包 | system.db.schema |
|---|---|
| 继承 | class CDbExpression » CComponent |
| 源码 | framework/db/schema/CDbExpression.php |
CDbExpression represents a DB expression that does not need escaping.
CDbExpression is mainly used in CActiveRecord as attribute values.
When inserting or updating a CActiveRecord, attribute values of
type CDbExpression will be directly put into the corresponding SQL statement
without escaping. A typical usage is that an attribute is set with 'NOW()'
expression so that saving the record would fill the corresponding column
with the current DB server timestamp.
Starting from version 1.1.1, one can also specify parameters to be bound for the expression. For example, if the expression is 'LOWER(:value)', then one can set params to be
Starting from version 1.1.1, one can also specify parameters to be bound for the expression. For example, if the expression is 'LOWER(:value)', then one can set params to be
array(':value'=>$value).公共属性
| 属性 | 类型 | 描述 | 被定义在 |
|---|---|---|---|
| expression | string | the DB expression | CDbExpression |
| params | array | list of parameters that should be bound for this expression. | CDbExpression |
公共方法
| 方法 | 描述 | 被定义在 |
|---|---|---|
| __call() | Calls the named method which is not a class method. | CComponent |
| __construct() | Constructor. | CDbExpression |
| __get() | Returns a property value, an event handler list or a behavior based on its name. | CComponent |
| __isset() | Checks if a property value is null. | CComponent |
| __set() | Sets value of a component property. | CComponent |
| __toString() | String magic method | CDbExpression |
| __unset() | Sets a component property to be null. | CComponent |
| asa() | Returns the named behavior object. | CComponent |
| attachBehavior() | Attaches a behavior to this component. | CComponent |
| attachBehaviors() | Attaches a list of behaviors to the component. | CComponent |
| attachEventHandler() | Attaches an event handler to an event. | CComponent |
| canGetProperty() | Determines whether a property can be read. | CComponent |
| canSetProperty() | Determines whether a property can be set. | CComponent |
| detachBehavior() | Detaches a behavior from the component. | CComponent |
| detachBehaviors() | Detaches all behaviors from the component. | CComponent |
| detachEventHandler() | Detaches an existing event handler. | CComponent |
| disableBehavior() | Disables an attached behavior. | CComponent |
| disableBehaviors() | Disables all behaviors attached to this component. | CComponent |
| enableBehavior() | Enables an attached behavior. | CComponent |
| enableBehaviors() | Enables all behaviors attached to this component. | CComponent |
| evaluateExpression() | Evaluates a PHP expression or callback under the context of this component. | CComponent |
| getEventHandlers() | Returns the list of attached event handlers for an event. | CComponent |
| hasEvent() | Determines whether an event is defined. | CComponent |
| hasEventHandler() | Checks whether the named event has attached handlers. | CComponent |
| hasProperty() | Determines whether a property is defined. | CComponent |
| raiseEvent() | Raises an event. | CComponent |
属性详情
expression
属性
public string $expression;
the DB expression
params
属性
（自版本 v1.1.1 可用）
public array $params;
list of parameters that should be bound for this expression. The keys are placeholders appearing in expression, while the values are the corresponding parameter values.
方法详情
__construct()
方法
|
public void __construct(string $expression, array $params=array (
))
| ||
| $expression | string | the DB expression |
| $params | array | parameters |
源码： framework/db/schema/CDbExpression.php#46 (显示)
public function __construct($expression,$params=array())
{
$this->expression=$expression;
$this->params=$params;
}
Constructor.
__toString()
方法
|
public string __toString()
| ||
| {return} | string | the DB expression |
源码： framework/db/schema/CDbExpression.php#56 (显示)
public function __toString()
{
return $this->expression;
}
String magic method