How can I have a one-way synonym in Solr? - solr

Question

I am trying to implement one way synonym or one way thesaurus(as in Endeca) in Solr. Where I search for camcorder I get result for camera also but not vice versa. I tried adding following in Synonyms.txt but seems to be not working as it is giving weird results:
camcorder => camera
And my schema.xml is:
<fieldType name="text_general" class="solr.TextField" positionIncrementGap="100" multiValued="true">
<analyzer type="index">
<tokenizer class="solr.ClassicTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.ClassicFilterFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" />
<filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
<filter class="solr.EdgeNGramFilterFactory" minGramSize="2" maxGramSize="15"/>
</analyzer>
<analyzer type="query">
<tokenizer class="solr.ClassicTokenizerFactory"/>
<filter class="solr.LowerCaseFilterFactory"/>
<filter class="solr.ClassicFilterFactory"/>
<filter class="solr.StopFilterFactory" ignoreCase="true" words="stopwords.txt" />
</analyzer>
</fieldType>

Answer 1

I think what you were looking for is:
camcorder => camera, camcorder
If you don't include camcorder on the right side, camcorder won't return any results if you search for "camcorder".

Answer 2

Since you're only expanding synonyms when you're indexing (where you have the SynonymFilter defined), camcorder will be changed to camera for each document on the way in. When you don't have the same expansion taking place when querying, Solr will still search for camcorder (as there is no SynonymFilter defined for the query analysis chain). There is no camcorder token in the index, so there will be no hit.
You'll have to expand synonyms when querying as well as when indexing to achieve what you want with one-way synonyms.