Lucene RangeQuery 没有正确过滤 [英] Lucene RangeQuery doesn't filter appropriately

问题描述

我正在使用 RangeQuery 来获取数量在 0 到 2 之间的所有文档.当我执行查询时，Lucene 也会给我数量大于 2 的文档.我在这里错过了什么?

I'm using RangeQuery to get all the documents which have amount between say 0 to 2. When i execute the query, Lucene gives me documents which have amount greater than 2 also. What am I missing here?

这是我的代码:

Term lowerTerm = new Term("amount", minAmount);
Term upperTerm = new Term("amount", maxAmount);

RangeQuery amountQuery = new RangeQuery(lowerTerm, upperTerm, true);

finalQuery.Add(amountQuery, BooleanClause.Occur.MUST);

这是我索引中的内容:

doc.Add(new Field("amount", amount.ToString(), Field.Store.YES, Field.Index.UN_TOKENIZED, Field.TermVector.YES));

推荐答案

UPDATE:就像@basZero在他的评论中所说，从Lucene 2.9开始，你可以添加数字字段到您的文档.只要记住使用 NumericRangeQuery 搜索时代替 RangeQuery.

UPDATE: Like @basZero said in his comment, starting with Lucene 2.9, you can add numeric fields to your documents. Just remember to use NumericRangeQuery instead of RangeQuery when you search.

Lucene 将数字视为单词，因此它们的顺序是字母顺序:

Lucene treats numbers as words, so their order is alphabetic:

0
1
12
123
2
22

这意味着对于 Lucene，12 介于 0 和 2 之间.如果要进行适当的数字范围，则需要索引数字零填充，然后执行 [0000 TO 0002] 的范围搜索.(您需要的填充量取决于预期的值范围).

That means that for Lucene, 12 is between 0 and 2. If you want to do a proper numerical range, you need to index the numbers zero-padded, then do a range search of [0000 TO 0002]. (The amount of padding you need depends on the expected range of values).

如果您有负数，只需为非负数添加另一个零.(错错了.查看更新)

If you have negative numbers, just add another zero for non-negative numbers. ( WRONG WRONG WRONG. See update)

如果您的数字包含小数部分，请保持原样，仅对整数部分进行零填充.

If your numbers include a fraction part, leave it as is, and zero-pad the integer part only.

例子:

<罢工>

-00002.12
-00001

000000
000001
000003.1415
000022

更新:负数有点棘手，因为 -1 按字母顺序排在 -2 之前.这篇文章给出了关于在 Lucene 中处理负数和一般数字的完整解释.基本上，您必须将数字编码"成使项目的顺序有意义的东西.

UPDATE: Negative numbers are a bit tricky, since -1 comes before -2 alphabetically. This article gives a complete explanation about dealing with negative numbers and numbers in general in Lucene. Basically, you have to "encode" numbers into something that makes the order of the items make sense.

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