i am using whoosh to index over 200,000 books. but i have encountered some problems with it.
the whoosh query parser returns NullQuery for words like "C#", "C++" with meta-characters in them and also for some other short words. this words are used in the title and body of some documents so i am not using keyword type for them. i guess the problem is in the analysis or query-parsing phase of searching or indexing but i can't touch my data blindly. can anyone help me to correct this issue. Tnx.
i fixed the problem by creating a StandardAnalyzer with a regex pattern that meets my requirements,here is the regex pattern:
'\w+[#+.\w]*'
this will make tokenizing of fields to be done successfully, and also the searching goes well.
but when i use queries like "some query++*" or "some##*" the parsed query will be a single Every query, just the '*'. also i found that this is not related to my analyzer and this is the Whoosh's default behavior. so here is my new question: is this behavior correct or it is a bug??
note: removing the WildcardPlugin from the query-parser solves this problem but i also need the WildcardPlugin.
now i am using the following code:
from whoosh.util import rcompile
#for matching words like: '.NET', 'C++' and 'C#'
word_pattern = rcompile('(\.|[\w]+)(\.?\w+|#|\+\+)*')
#i don't need words shorter that two characters so i don't change the minsize default
analyzer = analysis.StandardAnalyzer(expression=word_pattern)
... now in my schema:
...
title = fields.TEXT(analyzer=analyzer),
...
this will solve my first problem, yes. but the main problem is in searching. i don't want to let users to search using the Every query or *. but when i parse queries like C++* i end up an Every(*) query. i know that there is some problem but i can't figure out what it is.
I had the same issue and found out that StandardAnalyzer() uses minsize=2 by default. So in your schema, you have to tell it otherwise.
schema = whoosh.fields.Schema(
name = whoosh.fields.TEXT(stored=True, analyzer=whoosh.analysis.StandardAnalyzer(minsize=1)),
# ...
)
Related
I have a custom index for my products and I am using the Subset Analyzer. This Analyzer works great, but if you do field searches, it does not work.
For example, I have a document with the following fields:
"documentname", "My-Document-Name"
"tags", "1234,5678,9101"
"documentdescription", "This is a great Document, My-Document-Name."
When I just search "name AND tags:(1234)", I get this document in my results because it searches +_content:name.
-- However:
When I search "documentname:(name)^3.0 AND tags:(1234)", I do not get this document in my results.
Of course, when I do "documentname:(*name*)^3.0" I get a parse error saying: '*' or '?' not allowed as first character in WildcardQuery.
How can I either enable wildcard query in my custom CMS.Search webpart?
First of all you have to make sure that a field you checking is in the index with proper name. documentname might not be in the index it can be called _title, depends how you index is set up. Get lukeall and check your index (it should be in \CMS\App_Data\CMSModules\SmartSearch\YourIndexName). You can use luke to test your searches as well.
For examples there is no tags but there is documenttags field.
P.S. Wildcards are working and you are right you can't use them as a first character by default (lucene documentation says: You cannot use a * or ? symbol as the first character of a search), but there is a way to set it up in lucene.net, although i dont know if there are setting for that in Kentico. But i dont think you need wildcards, so your query should be (assuming you have documentname and documenttags in the index):
+(documentname:"My-Name" AND documenttags:"tag1")
and thanks for looking!
I have an instance of YouTrack with several custom fields, some of which are String-type. I'm implementing a module to create a new issue via the YouTrack REST API's PUT request, and then updating its fields with user-submitted values by applying commands. This works great---most of the time.
I know that I can apply multiple commands to an issue at the same time by concatenating them into the query string, like so:
Type Bug Priority Critical add Fix versions 5.1 tag regression
will result in
Type: Bug
Priority: Critical
Fix versions: 5.1
in their respective fields (as well as adding the regression tag). But, if I try to do the same thing with multiple String-type custom fields, then:
Foo something Example Something else Bar P0001
results in
Foo: something Example Something else Bar P0001
Example:
Bar:
The command only applies to the first field, and the rest of the query string is treated like its String value. I can apply the command individually for each field, but is there an easier way to combine these requests?
Thanks again!
This is an expected result because all string after foo is considered a value of this field, and spaces are also valid symbols for string custom fields.
If you try to apply this command via command window in the UI, you will actually see the same result.
Such a good question.
I encountered the same issue and have spent an unhealthy amount of time in frustration.
Using the command window from the YouTrack UI I noticed it leaves trailing quotations and I was unable to find anything in the documentation which discussed finalizing or identifying the end of a string value. I was also unable to find any mention of setting string field values in the command reference, grammer documentation or examples.
For my solution I am using Python with the requests and urllib modules. - Though I expect you could turn the solution to any language.
The rest API will accept explicit strings in the POST
import requests
import urllib
from collections import OrderedDict
URL = 'http://youtrack.your.address:8000/rest/issue/{issue}/execute?'.format(issue='TEST-1234')
params = OrderedDict({
'State': 'New',
'Priority': 'Critical',
'String Field': '"Message to submit"',
'Other Details': '"Fold the toilet paper to a point when you are finished."'
})
str_cmd = ' '.join(' '.join([k, v]) for k, v in params.items())
command_url = URL + urllib.urlencode({'command':str_cmd})
result = requests.post(command_url)
# The command result:
# http://youtrack.your.address:8000/rest/issue/TEST-1234/execute?command=Priority+Critical+State+New+String+Field+%22Message+to+submit%22+Other+Details+%22Fold+the+toilet+paper+to+a+point+when+you+are+finished.%22
I'm sad to see this one go unanswered for so long. - Hope this helps!
edit:
After continuing my work, I have concluded that sending all the field
updates as a single POST is marginally better for the YouTrack
server, but requires more effort than it's worth to:
1) know all fields in the Issues which are string values
2) pre-process all the string values into string literals
3) If you were to send all your field updates as a single request and just one of them was missing, failed to set, or was an unexpected value, then the entire request will fail and you potentially lose all the other information.
I wish the YouTrack documentation had some mention or discussion of
these considerations.
I have a Mongo search set up that goes through my entries based on numerous criteria.
Currently the easiest way (I know it's not performance-friendly due to using wildcards, but I can't figure out a better way to do this due to case insensitivity and users not putting in whole words) is to use regex wildcards in the search. The search ends up looking like this:
{ gender: /Womens/i, designer: /Voodoo Girl/i } // Should return ~200 results
{ gender: /Mens/i, designer: /Voodoo Girl/i } // Should return 0 results
In the example above, both searches are returning ~200 results ("Voodoo Girl" is a womenswear label and all corresponding entries have a gender: "Womens" field.). Bizarrely, when I do other searches, like:
{ designer: /Voodoo Girl/i, store: /Store XYZ/i } // should return 0 results
I get the correct number of results (0). Is this an order thing? How can I ensure that my search only returns results that match all of my wildcarded queries?
For reference, the queries are being made in nodeJS through a simple db.products.find({criteria}) lookup.
To answer the aside real fast, something like ElasticSearch is a wonderful way to get more powerful, performant searching capabilities in your app.
Now, the reason that your searches are returning results is that "mens" is a substring of "womens"! You probably want either /^Mens/i and /^Womens/i (if Mens starts the gender field), or /\bMens\b/ if it can appear in the middle of the field. The first form will only match the given field from the beginning of the string, while the second form looks for the given word surrounded by word boundaries (that is, not as a substring of another word).
If you can use the /^Mens/ form (note the lack of the /i), it's advisable, as anchored case-sensitive regex queries can use indexes, while other regex forms cannot.
$regex can only use an index efficiently when the regular expression has an anchor for the beginning (i.e. ^) of a string and is a case-sensitive match.
Am hoping someone with enough insight into the inner workings of Lucene might be able to point me in the right direction =)
I'll skip most of the surrounding irellevant code, and cut right to the chase. I have a Lucene index, to which I am adding the following field to the index (variables replaced by their literal values):
document.Add( new Field("Typenummer", "E5CEB501A244410EB1FFC4761F79E7B7",
Field.Store.YES , Field.Index.UN_TOKENIZED));
Later, when I search my index (using other types of queries), I am able to verify that this field does indeed appear in my index - like when looping through all Fields returned by Document.GetFields()
Field: Typenummer, Value: E5CEB501A244410EB1FFC4761F79E7B7
So far so good :-)
Now the real problem is - why can I not use a TermQuery to search against this value and actually get a result.
This code produces 0 hits:
// Returns 0 hits
bq.Add( new TermQuery( new Term( "Typenummer",
"E5CEB501A244410EB1FFC4761F79E7B7" ) ), BooleanClause.Occur.MUST );
But if I switch this to a WildcardQuery (with no wildcards), I get the 1 hit I expect.
// returns the 1 hit I expect
bq.Add( new WildcardQuery( new Term( "Typenummer",
"E5CEB501A244410EB1FFC4761F79E7B7" ) ), BooleanClause.Occur.MUST );
I've checked field lengths, I've checked that I am using the same Analyzer and so on and I am still on square 1 as to why this is.
Can anyone point me in a direction I should be looking?
I finally figured out what was going on. I'm expanding the tags for this question as it, much to my surprise, actually turned out to be an issue with the CMS this particular problem exists in. In summary, the problem came down to this:
The field is stored UN_TOKENIZED, meaning Lucene will store it excactly "as-is"
The BooleanQuery I pasted snippets from gets sent to the Sitecore SearchManager inside a PreparedQuery wrapper
The behaviour I expected from this was, that my query (having already been prepared) would go - unaltered - to the Lucene API
Turns out I was wrong. It passes through a RewriteQuery method that copies my entire set of nested queries as-is, with one exception - all the Term arguments are passed through a LowercaseStrategy()
As I indexed an UPPERCASE Term (UN_TOKENIZED), and Sitecore changes my PreparedQuery to lowercase - 0 results are returned
Am not going to start an argument of whether this is "by design" or "by design flaw" implementation of the Lucene Wrapper API - I'll just note that rewriting my query when using the PreparedQuery overload is... to me... unexpected ;-)
Further teachings from this; storing the field as TOKENIZED will eliminate this problem too, as the StandardAnalyzer by default will lowercase all tokens.
I want Lucene.NET to store a value while indexing a modified, stripped-down version of the stored value. e.g. Consider the value:
this_example-has some/weird (chars) 100%
I want it stored right like that (so that I can retrieve exactly that for showing in the results list), but I want lucene to index it as:
this example has some weird chars 100
(you see, like a "sanitized" version of the original value) for a simplified search.
I figure this would be the job of an analyzer, but I don't want to mess with rolling my own. Ideally, the solution should remove everything that is not a letter, a number or quotes, replacing the removed chars by a white-space before indexing.
Any suggestions on how to implement that?
This is because I am indexing products for an e-commerce search, and some have realy creepy names. I think this would improve search assertiveness.
Thanks in advance.
If you don't want a custom analyzer, try storing the value as a separate non-indexed field, and use a simple regex to generate the sanitized version.
var input = "this_example-has some/weird (chars) 100%";
var output = Regex.Replace(input, #"[\W_]+", " ");
You mention that you need another Analyzer for some searching functionality. Dont forget the PerFieldAnalyzerWrapper which will allow you to use different analyzers within the same document.
public static void Main() {
var wrapper = new PerFieldAnalyzerWrapper(defaultAnalyzer: new StandardAnalyzer(Version.LUCENE_29));
wrapper.AddAnalyzer(fieldName: "id", analyzer: new KeywordAnalyzer());
IndexWriter writer = null; // TODO: Retrieve these.
Document document = null;
writer.AddDocument(document, analyzer: wrapper);
}
You are correct that this is the work of the analyzer. And I'd start by using a tool like luke to see what the standard analyzer does with your term before getting into what to use -- it tends to do a good job stripping noise characters and words.