Lucene：搜索没有特定字段的文档

Question

class familyMember {
   String id;
   String name;
   String parentId; // Id of familyMember object which is parent of this member
}

if (parentId != null) {
    Query parentIdQuery = new TermQuery(new Term("parentID", parentId.toString()));
    booleanQuery.add(parentIdQuery, BooleanClause.Occur.MUST);
} else {
    QueryParser queryParser = new QueryParser(LUCENE_VERSION, "parentId"), analyzer);
    queryParser.setAllowLeadingWildcard(true);
    Query parentIdQuery = queryParser.parse("%%");
    booleanQuery.add(parentIdQuery, BooleanClause.Occur.MUST_NOT);
}

编辑1：我也试过这个，但同样的问题。

if (parentId != null) {
    Query parentIdQuery = new TermQuery(new Term("parentID", parentId.toString()));
    booleanQuery.add(parentIdQuery, BooleanClause.Occur.MUST);
} else {
    Query parentIdQuery = new TermQuery(new Term("parentID", "%%"));
    booleanQuery.add(parentIdQuery, BooleanClause.Occur.MUST_NOT);
}

Answer 1

好的，我找到解决办法了。诡计在里面

new ConstantScoreQuery(new FieldValueFilter());

解决方案：

if (parentId != null) {
    Query parentIdQuery = new TermQuery(new Term("parentID", parentId.toString()));
    booleanQuery.add(parentIdQuery, BooleanClause.Occur.MUST);
} else {
    Query parentIdQuery = new ConstantScoreQuery(new FieldValueFilter("parentID", true));
    booleanQuery.add(parentIdQuery, BooleanClause.Occur.MUST);

}