FilterElement QML Type

The OPC UA ContentFilterElement. 更多...

import 语句：	import QtOpcUa
Since:	QtOpcUa 5.13

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特性

firstOperand : variant
operatorType : enumeration
secondOperand : variant

详细描述

A content filter element contains an operator and operands. There are four different operator types which contain literal values, references to attributes of nodes or to other content filter elements.

A combination of one or more content filter elements makes a content filter which is used by the server to filter data for the criteria defined by the content filter elements. For example, the where clause of an event filter is a content filter which is used to decide if a notification is generated for an event.

QtOpcUa.FilterElement {
    operator: QtOpcUa.FilterElement.GreaterThanOrEqual
    firstOperand: QtOpcUa.SimpleAttributeOperand { ... }
    secondOperand: QtOpcUa.LiteralOperand { ... }
}

另请参阅 EventFilter .

特性文档编制

firstOperand : variant

First operand to be used with the operator. This can be one of SimpleAttributeOperand , AttributeOperand , LiteralOperand or ElementOperand .

operatorType : enumeration

The filter operator.

Possible operators for a FilterElement that are specified in OPC-UA part 4, Tables 115 and 116.

常量	值
`FilterElement.Equals`
`FilterElement.IsNull`
`FilterElement.GreaterThan`
`FilterElement.LessThan`
`FilterElement.GreaterThanOrEqual`
`FilterElement.LessThanOrEqual`
`FilterElement.Like`
`FilterElement.Not`
`FilterElement.Between`
`FilterElement.InList`
`FilterElement.And`
`FilterElement.Or`
`FilterElement.Cast`
`FilterElement.InView`
`FilterElement.OfType`
`FilterElement.RelatedTo`
`FilterElement.BitwiseAnd`
`FilterElement.BitwiseOr`

secondOperand : variant

Second operand to be used with the operator. This can be one of SimpleAttributeOperand , AttributeOperand , LiteralOperand or ElementOperand .