How to search arabic words in solr - search

In my solr schema.xml I defined product arabic name field as below
<field name="productNameArabic" type="text_ar" indexed="true" stored="true"/>
<fieldType name="text_ar" class="solr.TextField" positionIncrementGap="100">
<analyzer>
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_ar.txt" />
<filter class="solr.ArabicNormalizationFilterFactory"/>
<filter class="solr.ArabicStemFilterFactory"/>
</analyzer>
</fieldType>
In solr search I want to search with product name using Arabic letters. While searching, Arabic user can feel little default to search some product name. Because some characters need to mention while searching.
Ex: إ أ آ
In the above mentioned characters, user can get combination of shift key. Usually if Arabic people will mention “ ا “ character and will get the below combined words.
Ex: إبرا
In my solr schema.xml I defined product arabic name field as below

I was able to achieve desired functionality by adding ASCIIFoldingFilter, this filter is able to remove accents from different languages, to make them similar in index time.
<fieldType name="arabic" class="solr.TextField" positionIncrementGap="100">
<analyzer>
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.ASCIIFoldingFilterFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="lang/stopwords_ar.txt" />
<filter class="solr.ArabicNormalizationFilterFactory"/>
<filter class="solr.ArabicStemFilterFactory"/>
</analyzer>
</fieldType>
Some more information about this filter - here. Working code example - here

Related

Filter on solr splitting by list of strings

I've got this fieldType on my Solr implementation
<fieldType name="suggestion_text" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter class="solr.WordDelimiterFilterFactory"
generateWordParts="1"
generateNumberParts="1"
splitOnNumerics="1"
preserveOriginal="1"
/>
<filter class="solr.EdgeNGramFilterFactory" maxGramSize="100"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
This works fine for almost every model I've got. For example for models AB1234, I can search 1234 and it finds it. But there's a particular case that I want to include and I'm trying to find a better solution than the current one:
Let's say AB is the manufacturer and 1234 is the actual part number, but in my database they are saved as AB1234. It I've got an A0 manufacturer, and A01234 partnumber, with the current implementation if i search 1234 i wont find it.
I found a workaround transforming the EdgeNGramFilterFactory into a NGramFilterFactory, but that's not the solution I want. I want the Solr to be able to search excluding the first two characters if they are letter+number or in the extreme case, but I need it to search with A0 and without A0.
I don't know if I was clear. Anyway i tryied with regular expressions, creating a new field and using this filter on it:
<filter class="solr.PatternReplaceFilterFactory" pattern="(A0)" replacement="" replace="all" />
or
<filter class="solr.PatternReplaceFilterFactory" pattern="[a-zA-Z][0-9]" replacement="" replace="all" />
but this is not giving expected results.
Can you help me? Thank you
Please try the below field type for your problem.
<fieldType name="text_en_splitting_test" class="solr.TextField" positionIncrementGap="100" autoGeneratePhraseQueries="true">
<analyzer type="index">
<tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter class="solr.WordDelimiterGraphFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="1" catenateNumbers="1" splitOnNumerics="1" preserveOriginal="1"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
This worked for below search terms.
AB1234
AB
1234
Please find the screenshot of the solr analysis page for the suggested field type with the search terms.

Solr query that contains slash

I've found an interesting query for Solr and it returns search results, but I don't understand, what is the purpose of slash symbol between the words?
duties:health/nurse
Anybody knows? Please, help.
Simple. You can look at the analyzer chain to understand what happens.
My guess is that the analyzer chain turns the / into a space - which makes the query into
duties: health nurse
To find out your analyzer chain from the configuration - start by checking the type of the field
For example
<field name="health" type="text_general" indexed="true" stored="true" required="true"/>
Now we look for the definition of the type
<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" />
<!-- in this example, we will only use synonyms at query time
<filter class="solr.SynonymFilterFactory" synonyms="index_synonyms.txt" ignoreCase="true" expand="false"/>
-->
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" />
<filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
As you can see, we have an index analyzer and a query analyzer.
My query analyzer would turn / in the query into something else by using the StandardTokenizerFactory.
From the solr wiki:
solr.StandardTokenizerFactory
A good general purpose tokenizer that strips many extraneous characters and sets token types to meaningful values. Token types are only useful for subsequent token filters that are type-aware of the same token types. There aren't any filters that use StandardTokenizer's types.
I am thinking that health/nurse is being viewed as a string literal as there are no spaces between. Health / nurse should yield different results than health/nurse, correct? If so, then health/nurse must be an indexed term in your documents.

How can I implement Solr case insensitive and accent insensitive substring search with whitespaces?

I store 120000 wine records in a SQL Server database. Until now I've searched successfully for wine names by performing the following SQL:
WHERE (LOWER(Wine.name) LIKE '%" + (searchString) + "%'")
I am now in the process of switching over to using Solr. I would like to search for "clos rene" and get "Clos Réné" back. However Solr is returning all records that match 'Clos' and all records that match 'Réné'. I've have tried the following field definition:
<fieldType name="c_text" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
Could someone please help me define the correct field type so that I can reproduce my SQL query above to return case insensitive and accent insensitive results for multiple words with white space in between?
I have also experimented with wildcard searches using filed type 'string', but I can't get it to work as case-insensitive.
Try,
<fieldType name="c_text" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.ASCIIFoldingFilterFactory"/>
<filter class="solr.EdgeNGramFilterFactory" minGramSize="3" maxGramSize="50" side="front"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.KeywordTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.ASCIIFoldingFilterFactory"/>
</analyzer>
</fieldType>
EDIT: Ok now i get your question , added extra : <filter class="solr.EdgeNGramFilterFactory" minGramSize="3" maxGramSize="50" side="front"/> try this.

Search in solr with special characters

I have a problem with a search with special characters in solr.
My document has a field "title" and sometimes it can be like "Titanic - 1999" (it has the character "-").
When i try to search in solr with "-" i receive a 400 error. I've tried to escape the character, so I tried something like "-" and "\-". With that changes solr doesn't response me with an error, but it returns 0 results.
How can i search in the solr admin with that special character(something like "-" or "'"???
Regards
UPDATE
Here you can see my current solr scheme https://gist.github.com/cpalomaresbazuca/6269375
My search is to the field "Title".
excerpt from the schema.xml:
...
<!-- A general text field that has reasonable, generic
cross-language defaults: it tokenizes with StandardTokenizer,
removes stop words from case-insensitive "stopwords.txt"
(empty by default), and down cases. At query time only, it
also applies synonyms. -->
<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" enablePositionIncrements="true" />
<!-- in this example, we will only use synonyms at query time
<filter class="solr.SynonymFilterFactory" synonyms="index_synonyms.txt" ignoreCase="true" expand="false"/>
-->
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" enablePositionIncrements="true" />
<filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
...
<field name="Title" type="text_general" indexed="true" stored="true"/>
You are using the standard text_general field for the title attribute. This might not be a good choice. text_general is meant to be for huge chunks of text (or at least sentences) and not so much for exact matching of names or titles.
The problem here is that text_general uses the StandardTokenizerFactory.
<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" enablePositionIncrements="true" />
<!-- in this example, we will only use synonyms at query time
<filter class="solr.SynonymFilterFactory" synonyms="index_synonyms.txt" ignoreCase="true" expand="false"/>
-->
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" enablePositionIncrements="true" />
<filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
StandardTokenizerFactory does the following:
A good general purpose tokenizer that strips many extraneous
characters and sets token types to meaningful values. Token types are
only useful for subsequent token filters that are type-aware of the
same token types.
This means the '-' character will be completely ignored and be used to tokenize the String.
"kong-fu" will be represented as "kong" and "fu". The '-' disappears.
This does also explain why select?q=title:\- won't work here.
Choose a better fitting field type:
Instead of the StandardTokenizerFactory you could use the solr.WhitespaceTokenizerFactory, that only splits on whitespace for exact matching of words. So making your own field type for the title attribute would be a solution.
Solr also has a fieldtype called text_ws. Depending on your requirements this might be enough.
To search for your exact phrase put inverted commas round it:
select?q=title:"Titanic - 1999"
If you just want to search for that special character then you will need to escape it:
select?q=title:\-
Also check:
Special characters (-&+, etc) not working in SOLR Query
If you know exactly which special characters you dont want to use then you can add this to the regex-normalize.xml
<regex>
<pattern>-</pattern>
<substitution>%2D</substitution>
</regex>
This will replace all "-" with %2D, so when you search, as long as you search for %2D instead of the "-" it will work fine
I spent a lot of time getting this done. Here is a clear step-by-step things to be done to query special characters in SolR. Hope it helps someone.
Edit the schema.xml file and find the solr.TextField that you are
using.
Under both, "index" and query" analyzers modify the
WordDelimiterFilterFactory and add types="characters.txt" Something like:
<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100" multiValued="true">
<analyzer type="index">
<tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter catenateAll="0" catenateNumbers="0" catenateWords="0" class="solr.WordDelimiterFilterFactory" generateNumberParts="1" generateWordParts="1" splitOnCaseChange="1" types="characters.txt"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter catenateAll="0" catenateNumbers="0" catenateWords="0" class="solr.WordDelimiterFilterFactory" generateNumberParts="1" generateWordParts="1" splitOnCaseChange="1" types="characters.txt"/>
</analyzer>
</fieldType>
Ensure that you use WhitespaceTokenizerFactory as the tokenizer as
shown above.
Your characters.txt file can have entries like-
\# => ALPHA
# => ALPHA
\u0023 => ALPHA
ie:- pointing to ALPHA only.
Clear the data, re-index and query for the entered characters. It
will work.

Solr for Arabic

I'm using Solr to index documents in 3 langues(arabic, french and english), I have used this fieldType :
<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100">
<analyzer type="index">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" enablePositionIncrements="true"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.StandardTokenizerFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" enablePositionIncrements="true"/>
<filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
<filter class="solr.LowerCaseFilterFactory"/>
</analyzer>
</fieldType>
Everything was good, but in arabic language when I put this request to search a word like حقل Solr doen't find the word, but when I put the word in oppositeلقح from left to right Solr find the word and return result.
Can I have result for arabic words ?
I'm going to turn Daniel's clever analysis here to an answer for the record. Don't vote for this, just go find something of his to vote for :-)
There are two ways to get a directionality mismatch with RTL text. You can be indexing it backwards, or you can be querying it backwards. A simple HTML form querying Solr will never mess up directionality. In this care, khaled was extracting text from a PDF using a library that falls victim to the tendency of PDFs to contain 'visual-order' text rather than 'logical order'. So the index was full of backwards Arabic. To fix this, he will have to come up with a working library that extracts text from pdfs.
Forcing Apache Tika to use the latest Apache PDFbox might help, or his PDF may be so quirky that even the latest PDFBox can't handle it. In which case he has a hard problem.

Resources