DDS_TopicQuerySelection Struct Reference

<<extension>> Specifies the data query that defines a DDS_TopicQuery More...

Data Fields
char *	filter_class_name
	The name of the filter to use. More...
char *	filter_expression
	The filter expression. More...
struct DDS_StringSeq	filter_parameters
	The query parameters. More...
DDS_TopicQuerySelectionKind	kind
	Indicates whether the sample selection is limited to cached samples or not. More...

Detailed Description

<<extension>> Specifies the data query that defines a DDS_TopicQuery

The query format is similar to the expression and parameters of a DDS_QueryCondition or a DDS_ContentFilteredTopic, as described in DDS_DomainParticipant_create_contentfilteredtopic_with_filter.

There are two special queries:

• DDS_TOPIC_QUERY_SELECTION_SELECT_ALL
• DDS_TOPIC_QUERY_SELECTION_USE_READER_CONTENT_FILTER

See also

Queries and Filters Syntax

Field Documentation

filter_class_name

char* DDS_TopicQuerySelection::filter_class_name

The name of the filter to use.

Name of content filter to use. Must be one of the built-in filter names or previously registered with DDS_DomainParticipant_register_contentfilter on the same DDS_DomainParticipant.

Built-in filter names are DDS_SQLFILTER_NAME and DDS_STRINGMATCHFILTER_NAME.

[default] See DDS_TOPIC_QUERY_SELECTION_USE_READER_CONTENT_FILTER

filter_expression

char* DDS_TopicQuerySelection::filter_expression

The filter expression.

The expression to filter samples in the DataWriters. It follows the format described in Queries and Filters Syntax.

[default] See DDS_TOPIC_QUERY_SELECTION_USE_READER_CONTENT_FILTER

See also

Queries and Filters Syntax

filter_parameters

struct DDS_StringSeq DDS_TopicQuerySelection::filter_parameters

The query parameters.

[default] See DDS_TOPIC_QUERY_SELECTION_USE_READER_CONTENT_FILTER

See also

DDS_DomainParticipant_create_contentfilteredtopic_with_filter.

kind

DDS_TopicQuerySelectionKind DDS_TopicQuerySelection::kind

Indicates whether the sample selection is limited to cached samples or not.

[default] DDS_TOPIC_QUERY_SELECTION_KIND_HISTORY_SNAPSHOT