排序规则区域设置和默认参数
在此页面上
版本 3.4 中的新增功能。
排序规则允许用户为字符串比较指定特定于语言的规则,例如字母大小写和重音符号规则。
行为
某些排序规则语言环境会有一些变体,这些变体采用特定于语言的特殊规则。若要指定语言环境变体,请使用以下语法:
{ "locale" : "<locale code>@collation=<variant>" }
例如,如要使用中文排序规则的unihan
变体:
{ "locale" : "zh@collation=unihan" }
有关排序规则行为和语法的完整说明,请参阅排序规则页面。
支持的语言和区域设置
MongoDB 排序规则功能支持以下语言。下表列出了支持的语言以及由 ICU 区域设置ID 定义的关联区域设置。 [1 ]
|
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提示
要明确指定简单的二进制比较,请将 locale
的值指定为 "simple"
。
[1] | 要请求对区域设置的支持,请向服务器项目提交 JIRA 工单 |
排序规则默认参数
排序规则文档包含多个可选参数以及必填的 locale
参数。根据您使用的 locale
,默认参数可能会有所不同。请参阅排序规则页面,获取排序规则语法的完整说明。
以下默认参数对于所有区域设置都是一致的:
caseLevel : false
strength : 3
numericOrdering : false
maxVariable : punct
下表显示默认排序规则参数,这些参数可能因区域设置而异:
locale | caseFirst | 替代方案 | normalization | backwards |
---|---|---|---|---|
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