I presume that you mean a missing field, not a blank field. You can do
this by using TermRangeQuery and passing null for term values. A null
value means that it's an open end ([A To *] or [* TO Z]), two null
values means it will match anything ([* TO *]). The main difference
compared to MatchAllDocsQuery is that TermRangeQuery still requires the
field to be present.
var query = new BooleanQuery();
query.Add(new MatchAllDocsQuery(), BooleanClause.Occur.MUST);
query.Add(new TermRangeQuery("field", null, null, true, true),
BooleanClause.Occur.MUST_NOT);
query.ToString() gives "+*:* -field:[* TO *]"
On 2012-06-14 21:20, Trevor Watson wrote:
I was wondering if there is a way to search for a field being blank.
We keep track of file extensions in our software and would like to do
a search for files that don't have an extension.
We could do a search for all documents (we keep a "Generic all field"
with "SelectAll" as the only Term) and then exclude * from the
fileExtension field, but that could result in a ridiculous number of
extensions that have to be run as "excluded".
Is there a way to search for field = blank?
Thanks in advance.
Trevor
