Reiterating again in the solr returned result set

Hi All I am given a requirement to check whether the user entered word is already entered by some other user. It has been suggested to do a solr search for this. Following is the schema for the word field type Exact_Word" omitPositions="true" termVectors="false" omitTermFreqAndPositions="true" c

Difference between search strings

Can someone please tell me the difference between searching a text in the following ways 1. q=Exact_Word:"samplestring" -> What does it tell to solr ? 2. q=samplestring&qf=Exact_Word -> What does it tell to solr ? 3. q="samplestring"&qf=Exact_Word -> What does it tell to solr ? I think the