MongoDB如何将索引定义从一个集合复制到另一个集合?

问题描述：

我知道有一种方法可以执行db.collection.getIndexes()，该方法将列出为集合定义的所有索引.有没有办法将这些索引定义复制并创建到另一个集合?

I know there's a way to do db.collection.getIndexes() Which will list all the indexes defined for a collection. Is there a way to copy and create those index definitions to another collection?

有很多，我不想一个接一个地做.

There's a lot of them and I don't want to do them one by one.

关于重复的问题评论:我不希望复制收藏集.我希望以可以应用于其他集合的格式导出索引.

regarding the duplicated question comment: I do not wish to copy a collection. I wish to export indexes in a format that I can apply to another collection.

答

例如，我有一个现有的 user 集合，其索引为 _id _ ， name_1 ，电子邮件_1 和网站_1

For example I have one existing user collection with indexes _id_, name_1, email_1 and website_1

然后我有另一个名为 usertest 的集合，我想将索引从 user 集合复制到 usertest 集合.以下命令适用于这种情况:

Then I have another collection called usertest, I want to copy indexes from user collection to usertest collection. The following commands works for this scenario:

同时复制索引键和索引选项

Copy both index key and index options

var indexes = db.user.getIndexes();

indexes.forEach(function(index){
    delete index.v;
    delete index.ns;
    var key = index.key;
    delete index.key
    var options = [];
    for (var option in index) {
        options.push(index[option]);
    }
   db.usertest.createIndex(key, options);
});

仅复制索引键(批处理)

Copy index key only (batch processing)

var indexKeys = db.user.getIndexKeys();
db.usertest.createIndexes(indexKeys);

希望这会有所帮助.这是文档: createIndexes

Hope this will be helpful. Here's the doc: createIndexes

MongoDB如何将索引定义从一个集合复制到另一个集合?

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