I just got started looking at using Solr as my search web service. I don't know whether Solr supports these query types:
Startswith
Exact Match
Contain
Doesn't Contain
In the range
Could anyone guide me how to implement those features in Solr?
Cheers,
Samnang
Solr is capable of all those things but to adequately explain how to do each of time an answer would become a mini-manual for Solr.
I'd suggest you read the actual manual and tutorials linked from the Solr homepage.
In short though:
Startswith can be implemented using Lucene wildcards.
Exact matches will only be found if a field is not tokanized. I.e. the entire field is viewed as a single token.
Contain is the default search format. I.e. a search for "John" will find any document's whose search field contains the value "John". Prefixing with - (e.g. "-John" will only find documents that do not contain John).
Ranges (be they date or integer) are possible and quite powerful, example date:[* TO NOW] would find any document whose date is not in the future.
Related
I am working on integrating Elastic Search in my existing Django REST application. I am using the django-dsl-drf module provided in the link below:
https://django-elasticsearch-dsl-drf.readthedocs.io/
In their documentation 'exclude' query param is provided. But the query only when we provide the full field value.
search-url?exclude=<field-value
For eg: If I have a value 'Stackoverflow' in field 'name'. I'll have to provide query param a
?name__exclude=Stackoverflow to exclude records having 'Stackoverflow' as name in the result. I would like to implement a search in such a way that when I provide 'over', I need to exclude these records, similar to ?name__exclude=over
I checked the above tutorial, but I couldn't find it. Is there any work around so that I can exclude records, fields containing terms instead of providing full field value, which is also case-insensitive.
Thanks a lot.
Using the contains functional filter, you can target documents that have their name field value containing the characters over anywhere in their terms:
?name__contains=over
However, as far as I know, there is no way to negate that filter in django-dsl-drf. You can create an issue requesting that feature, though, because odds are high that you're not the only who needs that, since it's a pretty common way of searching.
I'm a Django newbie doing a primitive website. I installed haystack and Whoosh as its search engine cause it was the simplest thing to do. It works fine, but there is a problem and I don't know how to Google it. I have some categories on my site and I have indexed their names to search. So, when a user enters "Computing" it finds the computing category and links to it. But there is a problem. If a user enters "Comp" into search field, it doesn't find "Computing" at all. Is this something that can be configured and how?
EDIT:
What else have I tried? Installing haystack 2.0, following this tutorial, installing solr instead of whoosh, trying Ngram fields, rebuilding indexes 10 times, rewriting search_indexes.py. Everything. Doesn't work. If I type in Comp, it doesn't find Computing. Is there anything else I could do? I have noticed that in the tutorial above, everything works like a charm instantly.
When you do the usual:
SearchQuerySet().filter(title='Computing')
in Haystack 1.x, it filters on everything exactly matching 'Computing'.
You can change that behaviour by using Haystack's Field Lookups, for example, using 'contains' will filter on anything containing the given string (Computing, Utingcomp, Comp):
SearchQuerySet().filter(title__contains='Comp')
In Haystack 2.x, the default filter is 'contains', so it should behave as you would expect it to "out-of-the-box"
Check out the documentation on autocomplete. You need to setup your indices to support Ngram's, but this should be exactly what you need.
from haystack.query import SearchQuerySet
SearchQuerySet().autocomplete(content_auto='old')
# Result match things like 'goldfish', 'cuckold' & 'older'.
So, if I'm understanding, what you're looking for is the equivalent of 'LIKE' in SQL.
The problem is search engines that back Haystack aren't like an RDBMS.
The low level implementation of this filter will involve using wildcard characters but most of the Haystack backends don't support a leading wildcard, something required for an icontains/endswith filter. However, since most backends support trailing wildcards, Haystack 2.x includes a startswith filter. The only case this doesn't handle is searching for the end of a word, which doesn't look to be possible.
So, if you have indexed:
"Look at our great discounts in Computer section"
Then the following Haystack query DO match:
SearchQuerySet().filter(title__startswith='comp')
# match!
Notice the difference between Django vs. Haystack startswith filters. Django startswith will match at the beginning of the complete sentence (i.e. a CharField), but the Haystack one will match at the beginning of a token (i.e. each word in a complete sentence).
Hope it helps!
In my field the content is "example".
I want to find not only the exact word "example", I also want to find "examp". How can I do that? Are there any options. Can't find anything.
If you just want to search for objects starting with some string, then just look at Haystack SearchQuerySet API documentation. It resembles the Django QuerySet API, so it is possible to write:
SearchQuerySet().filter(content__startswith='examp')
SearchQuerySet().filter(content__contains='examp')
or whatever you want.
But there is also something deeper in this question. I don't think you really need to. Because of the way search engines works - when someone searches for e.q. 'monitoring' it gets stemmed (it is process of getting something similar to root of the word - so we will have f.e. 'monitor' from 'monitoring') and that will be searched for in fact. Also everything in search indexes gets stemmed, so searching for monitor will return results containing f.e. 'monitors', 'monitoring', 'monitorize' etc.
I'd like to pass some parameters to Solr that should afflict the weighting of the results (I do not want to filter away results that do not match these criterias).
E.g. I'd like to have a language attribute, and if i pass the user's language to the search engine I'd like to have the results matching the language listed first. As a newbie to Solr I'd like to know if and how this is possible!
Yes, that's possible by using boost functions. See this FAQ entry or the description of boost functions for the DisMaxQueryPlugin (the dismax query parser is the default parser).
I've got a Haystack/xapian search index for django.contrib.auth.models.User. The template is simply
{{object.get_full_name}}
as I intend for a user to type in a name and be able to search for it.
My issue is this: if I search, say, Sri (my full first name) I come up with a result for the user object pertaining to my name. However, if I search Sri Ragh - that is, my full name, and part of my last name, I get no results.
How can I set Haystack up so that I can get the appropriate results for partial queries?
(I essentially want it to search *Sri Ragh*, but I don't know if wildcards would actually do the trick, or how to implement them).
This is my search query:
results = SearchQuerySet().filter(content='Sri Ragh')
I use to have a similar problem, as workaround or maybe a Fix you can change the query lookup
results = SearchQuerySet().filter(content__startswith='Sri Ragh')
The issue is that django-haystack doesn't implement all lingos from search engines. Of course you can do this.
results = SearchQuerySet().raw_search('READ THE SEARCH ENGINE QUERY SYNTAX FOR GET WILDCARD LOOKUPS')
As Django-haystack says, this is not portable.
You can use icontains or startswith.
Be careful with this one, if a query is for example 'r', this will bring you all 'Model' entities that have a 'r' in its content.
Model.objects.filter(content__icontains=query)
Model.objects.filter(content__startswith=query)
Look at the documentation