Solr查询字段回退

Question

I have the following fields indexed in Solr:

• FIELD_1
• FIELD_2
• FIELD_3

I would like to search for a document where FIELD_3=X but if FIELD_3 is empty (or non existent in the document), to search in FIELD_2, and then in FIELD_1

Is this kind of query possible in Solr ?

Thank you

Answer 1

Assuming that you only want to search against FIELD2 and FIELD1 if the previous fields are empty (and not if they have a value, but it didn't generate a hit), something like:

q=FIELD3:foo OR (FIELD2:foo AND NOT FIELD3:[* TO *]) OR (FIELD1:foo AND NOT FIELD2:[* TO *] AND NOT FIELD3:[* TO *])

should work.