why is "!term f=" added to my search query?

[Alex Romanin]

I can't find the answer to this anywhere! Is it legacy Solr?

I have facets configured as Strings (plural) multivalued string fields.

this works:

fq=fq=gpes_str%3ALondon

but in search_builder_spec.rb blacklight converts this to the following which does not return any results. I can override this following the instructions but why does it do this? I can't find any relevant documentation explaining what this syntax means...

fq={!term+f%3Dgpes_str}London

[Benjamin Armintor]

The part of the query in curly brackets is identifying the query parser to be used for this filter (the 'term' parser) and the relevant term for the query ('gpes_str'). The part after the brackets is the value to use for the query ('London'). Using the term parser on a text field tells Solr not to apply further analysis to the value, which makes it useful for turning a facet into an exactly-matching refining query.

This is documented in the latest version of Solr here: https://solr.apache.org/guide/8_8/other-parsers.html#term-query-parser

You can see the originating commit for this behavior here: https://github.com/projectblacklight/blacklight/commit/8cb787c630880411c519978d7558dae03c09022a

Prior to this change Blacklight used the 'raw' parser for turning facets into filters (that parser is documented in the same page of Solr documentation linked above).

I am assuming there is a missing ampersand in your query string under "this works" above? The other value for fq there ('gpes_str:London') is going through the standard parser, I think.

- Ben

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[Bill Dueber]

tl;dr — {!term f=gpes_str}London is exactly the same as gpes_str:"London" for this particular query. 

The {!query_parser_type f=field_name}query_words syntax is something you don’t see super often when people make queries by hand — they’re generally different/safer ways to specify parsing rules for a specific (part of) your query.

The term query parser doesn’t do any analysis (tokenizing, lowercasing, whatever), which is exactly what you want when doing a facet query — not a big change for this query, but you could do {!term f=gpes_str}Tower of London as well and no tokenization would happen. Other common ones are {!lucene and {!edismax (for those query parsers) and things like the field query parser, where {!field f=myfield}Hi there is equivalent to myfield:"Hi there" but you don’t have to worry about enclosing/escaping double quotes by yourself.

These can be especially useful when combining different query parsers using “localparams” syntax, so you can use the normal lucene AND/OR/NOT syntax, but have different clauses parsed/analyzed in different ways.

A list of the default available ones are at https://solr.apache.org/guide/8_8/other-parsers.html

On Fri, Apr 16, 2021 at 10:11 AM Alex Romanin <alexr...@gmail.com> wrote:

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Bill Dueber
Library Systems Programmer
University of Michigan Library

[Alex Romanin]

aha! brilliant, thankyou so much for the speedy response!

Sorry for the typo, it should have been simply:

this works:

fq=gpes_str%3ALondon

So I understand that it would surely work perfectly if my facet field was a singular String field but I'm using a Strings (plural) multivalued string field which would work through the normal/raw parser and not the term one.

Thanks so much for the links and the help, it's really appreciated!

[Alex Romanin]

brilliant, thanks for the extra info - works perfectly on single string field but not multivalued facet that I'm using. Much appreciated!