MongoDB diacriticInSensitive 搜索未按预期显示所有重音(带有变音符号的单词)行，反之亦然

Question

我有一个具有以下结构的文档集合

uid, name

有索引

db.Collection.createIndex({name: "text"})

它包含以下数据

1, iphone
2, iphóne
3, iphonë
4, iphónë

当我对 iphone 进行文本搜索时我只得到两条记录，这是出乎意料的

actual output
--------------
1, iphone
2, iphóne

如果我搜索 iphonë

db.Collection.find( { $text: { $search: "iphonë"} } );

I am getting
---------------------
3, iphonë
4, iphónë

但实际上我期待以下输出

db.Collection.find( { $text: { $search: "iphone"} } );
db.Collection.find( { $text: { $search: "iphónë"} } );

    Expected output
    ------------------
    1, iphone
    2, iphóne
    3, iphonë
    4, iphónë

我在这里遗漏了什么吗？如何通过搜索 iphone 或 iphónë 获得超出预期的输出？

Answer 1

自 mongodb 3.2 以来，text indexes变音符号不敏感:

With version 3, text index is diacritic insensitive. That is, the index does not distinguish between characters that contain diacritical marks and their non-marked counterpart, such as é, ê, and e. More specifically, the text index strips the characters categorized as diacritics in Unicode 8.0 Character Database Prop List.

所以下面的查询应该有效:

db.Collection.find( { $text: { $search: "iphone"} } );
db.Collection.find( { name: { $regex: "iphone"} } );

但看起来分音符 ( ¨ ) 存在错误，即使它在 unicode 8.0 列表中被分类为变音符号(JIRA 上的问题:SERVER-29918)

解决方案

从 mongodb 3.4 开始，您可以使用 collation它允许您执行这种查询:

例如，要获得预期的输出，请运行以下查询:

db.Collection.find({name: "iphone"}).collation({locale: "en", strength: 1})

这将输出:

{ "_id" : 1, "name" : "iphone" }
{ "_id" : 2, "name" : "iphône" }
{ "_id" : 3, "name" : "iphonë" }
{ "_id" : 4, "name" : "iphônë" }

在排序规则中，strength 是要执行的比较级别

• 1 : 仅基本字符
• 2 : 变音符号敏感
• 3 :区分大小写 + 区分变音符号