如何查看或修改在 MongoDB 集合上设置的排序规则选项? [英] How to view or modify collation options set on a MongoDB collection?

问题描述

您如何修改我们在创建时为集合设置的选项?我们如何查看已设置的选项?

How do you modify the options that we set on a collection at the time of creation? And how do we view the options already set?

例如，如果我们看到整理选项，我会创建一个这样的集合:

If we see the collation option for example, I create a collection like this:

db.createCollection("words", {collation : {locale :"es", strength : 2}});

并添加几个文件:

db.words.insertOne({text : "Résumé"});
db.words.insertOne({text : "Resume"});
db.words.insertOne({text : "résumé"});
db.words.insertOne({text : "resume"});

如何将这个集合的排序规则的强度更改为 3?我怎么看变化?我在 db 对象或 db.words 对象或文档中没有看到任何可用的相关函数！

How do I change the strength of the collation on this collection to 3? how do I see the change? I do not see any relevant functions available on the db object or db.words object or in the docs!

推荐答案

您如何修改我们在创建时为集合设置的选项?

How do you modify the options that we set on a collection at the time of creation?

在 MongoDB 3.6 中，只能在创建集合时指定默认排序规则选项.不支持修改默认排序规则选项.

As at MongoDB 3.6, the default collation options can only be specified when a collection is created. There is no support for modifying the default collation options.

但是，如果您想使用除默认值以外的排序规则选项，您可以为 支持排序的操作，例如find() 和aggregate().

However, if you want to use collation options other than the default you can specify a collation document for operations that support collation, such as find() and aggregate().

我们如何查看已设置的选项?

how do we view the options already set?

有几种方法.

db.getCollectionInfos() shell helper 显示额外的集合信息，例如排序规则默认值:

The db.getCollectionInfos() shell helper displays additional collection information such as collation defaults:

db.getCollectionInfos({name:'words'})[0].options.collation
{
  "locale": "es",
  "caseLevel": false,
  "caseFirst": "off",
  "strength": 2,
  "numericOrdering": false,
  "alternate": "non-ignorable",
  "maxVariable": "punct",
  "normalization": false,
  "backwards": false,
  "version": "57.1"
}

您还可以检查查询计划器使用的默认排序规则选项:

You can also check the default collation options used by the query planner:

> db.words.find().explain().queryPlanner.collation
{
  "locale": "es",
  "caseLevel": false,
  "caseFirst": "off",
  "strength": 2,
  "numericOrdering": false,
  "alternate": "non-ignorable",
  "maxVariable": "punct",
  "normalization": false,
  "backwards": false,
  "version": "57.1"
}

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