Solr search query does not consider special character

Question

I have indexed in solr shop names like

H&M
Lotte & Anna
fan & more
Tele2
Pure Tea

I have the following two issues (with importance in priority)

1. if I search for "H&M" I will never get any result. If I search for "te & Ann" I get the expected results.

2. if I search for "te & an" the results I get are Tele2 and Pure Tea whereas I would have expected "Lotte & Anna" to appear first in the list.

It appears as if the & character is not taken into consideration. What am I doing wrong here?

These are my analysers for the specific field (both query and index)

<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100">
    <analyzer type="index">
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
        <filter class="solr.EdgeNGramFilterFactory" minGramSize="2" maxGramSize="15" side="front"/>
    </analyzer>
    <analyzer type="query">
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
        <filter class="solr.LowerCaseFilterFactory"/>
    </analyzer>
</fieldType>

Ok, so the 1st problem was addressed with the WordDelimiterFilterFactory specifying & => ALPHA in the wdfftypes.txt and changing switching from the StandardTokenizerFactory to the WhitepsaceTokenizerFactory

<tokenizer class="solr.WhitespaceTokenizerFactory"/>
<filter class="solr.WordDelimiterFilterFactory" types="wdfftypes.txt"/>

(edited in both analyser and query).

2nd question still remains. In the debugQuery I get the following

"debug": {
    "rawquerystring": "te & an",
    "querystring": "te & an",
    "parsedquery": "text:te text:an",
    "parsedquery_toString": "text:te text:an",
    "explain": {
      "": "\n0.8152958 = (MATCH) product of:\n  1.6305916 = (MATCH) sum of:\n    1.6305916 = (MATCH) weight(text:te in 498) [DefaultSimilarity], result of:\n      1.6305916 = score(doc=498,freq=1.0 = termFreq=1.0\n), product of:\n        0.8202942 = queryWeight, product of:\n          5.300835 = idf(docFreq=87, maxDocs=6491)\n          0.15474811 = queryNorm\n        1.9878132 = fieldWeight in 498, product of:\n          1.0 = tf(freq=1.0), with freq of:\n            1.0 = termFreq=1.0\n          5.300835 = idf(docFreq=87, maxDocs=6491)\n          0.375 = fieldNorm(doc=498)\n  0.5 = coord(1/2)\n"
    },

so, what should I modify so that the weights shift in favour of the desired result?

Answer 1

Use "NGramFilterFactory" instead of "EdgeNGramFilterFactory". That way, "Lotte & Anne", gets indexed into "lo, ot, tt, te, lot, ott, tte, lott, otte, lotte" and "an, nn, ne, ann, nne, anne". so when you search for "tte & ann", the document will match.