Hibernate 搜索六：可聚合字段不区分大小写搜索，同时保留区分大小写的聚合结果

Question

I have used the new aggregation functionality of Hibernate Search 6 to develop a classic "faceted search" interface, in which the various search fields in the UI are accompanied by the most popular choices taken from the aggregation data of the SearchResult . This works beautifully.

However, I would like to allow the users to be able to search these fields case-insensitively, so that they are not limited to choosing from the aggregation results and are not penalised for typing in the wrong case.

I have applied a lowercase normalizer to the aggregable field definition, which allows me to search case-insensitively, but if I do this all of the aggregation data retrieved from the SearchResult , and presented to the user, is also in lowercase.

Is there a way to allow case-insensitive searches while retaining the original case in the aggregation results?

I have attempted to use projectable( Projectable.YES ) in my field definition, in the hope that this would return the original case, but it had no effect.

My current field template definition is:

indexSchemaObjectField.fieldTemplate( "template", f -> f.asString()
    .aggregable( Aggregable.YES )
    .projectable( Projectable.YES )
    .normalizer( "lowercase")
).multiValued();

and my lowercase normalizer is defined as:

luceneAnalysisConfigurationContext.normalizer( "lowercase" )
    .custom()
    .tokenFilter( "lowercase" );

I'm using the Lucene backend.

Answer 1

Ideally you'd use multi-fields, but that's not available at the moment ( https://hibernate.atlassian.net/browse/HSEARCH-3465 ).

In the meantime, I would rely on two separate fields:

// Declare one field for aggregations
// (do this first, so that the glob is matched first)
indexSchemaObjectField.fieldTemplate( "template", f -> f.asString()
    .aggregable( Aggregable.YES )
)
.matchingPathGlob("*_agg")
.multiValued();

// Declare one field for search
indexSchemaObjectField.fieldTemplate( "template", f -> f.asString()
    .normalizer( "lowercase")
).multiValued();

Then in your bridge, you would duplicate the value: first populate the field "<fieldname>" , then the field "<fieldname>_agg" with the same value.

Finally, when searching, you would use "<fieldname>" for predicates, but "<fieldname>_agg" for aggregations.