db.collection.dropIndex()

Definition定义

db.collection.dropIndex(index)

Important

mongosh Method

This page documents a mongosh method. This is not the documentation for database commands or language-specific drivers, such as Node.js.

For the database command, see the dropIndexes command.

For MongoDB API drivers, refer to the language-specific MongoDB driver documentation.

For the legacy mongo shell documentation, refer to the documentation for the corresponding MongoDB Server release:

mongo shell v4.4

Drops or removes the specified index from a collection.从集合中删除或删除指定的索引。

Note

• You cannot drop the default index on the _id field.不能删除_id字段上的默认索引。
• Starting in MongoDB 4.2, you cannot specify db.collection.dropIndex("*") to drop all non-_id indexes. 从MongoDB 4.2开始，您不能指定db.collection.dropIndex("*")来删除所有非_id索引。Use db.collection.dropIndexes() instead.请改用db.collection.dropIndexes()。

To get the index name or the index specification document for the db.collection.dropIndex() method, use the db.collection.getIndexes() method.若要获取db.collection.dropIndex()方法的索引名称或索引规范文档，请使用db.collection.getIndexes()方法。

The db.collection.dropIndex() method takes the following parameter:db.collection.dropIndex()方法采用以下参数：

Parameter参数	Type类型	Description描述
index	string or document	Required.必要的。Specifies the index to drop. You can specify the index either by the index name or by the index specification document.指定要删除的索引。可以通过索引名称或索引规范文档指定索引。 To drop a text index, specify the index name.若要删除text索引，请指定索引名称。 Starting in MongoDB 4.2, you cannot specify "*" to drop all non-_id indexes. 从MongoDB 4.2开始，您不能指定"*"来删除所有非_id索引。Use db.collection.dropIndexes() instead. 请改用db.collection.dropIndexes()。 New in version 4.4:4.4版新增：If an index specified to db.collection.dropIndex() is still building, db.collection.dropIndex() attempts to stop the in-progress build. 如果指定给db.collection.dropIndex()的索引仍在生成中，则db.collection.dropIndex()会尝试停止正在进行的生成。Stopping an index build has the same effect as dropping the built index. 停止索引生成与删除生成的索引具有相同的效果。Prior to MongoDB 4.4, db.collection.dropIndex() returned an error if the specified index was still building. 在MongoDB 4.4之前，如果指定的索引仍在构建中，db.collection.dropIndex()会返回一个错误。See Stop In-Progress Index Builds for more complete documentation. 有关更完整的文档，请参阅停止正在进行的索引生成。

Behavior行为

Starting in MongoDB 5.2, you can use db.collection.dropIndex() to drop existing indexes on the same collection even if there is a build in progress on another index. 从MongoDB 5.2开始，您可以使用db.collection.dropIndex()删除同一集合上的现有索引，即使在另一个索引上正在进行构建。In earlier versions, attempting to drop a different index during an in-progress index build results in a BackgroundOperationInProgressForNamespace error.在早期版本中，在正在进行的索引生成过程中尝试删除其他索引会导致BackgroundOperationInProgressForNamespace错误。

Example实例

Consider a pets collection. Calling the db.collection.getIndexes() method on the pets collection returns the following indexes:考虑一下pets集合。对pets集合调用db.collection.getIndexes()方法将返回以下索引：

[
   {
      "v" : 2,
      "key" : {
         "_id" : 1
      },
      "name" : "_id_"
   },
   {
      "v" : 2,
      "key" : {
         "cat" : -1
      },
      "name" : "catIdx"
   },
   {
      "v" : 2,
      "key" : {
         "cat" : 1,
         "dog" : -1
      },
      "name" : "cat_1_dog_-1"
   }
]

The single field index on the field cat has the user-specified name of catIdx [1] and the index specification document of { "cat" : -1 }.字段cat上的单个字段索引具有用户指定的名称catIdx[1]和索引规范文档{ "cat" : -1 }。

To drop the index catIdx, you can use either the index name:要删除索引catIdx，可以使用以下任一索引名称：

db.pets.dropIndex( "catIdx" )

Or you can use the index specification document { "cat" : -1 }:或者，您可以使用索引规范文档{ "cat" : -1 }：

db.pets.dropIndex( { "cat" : -1 } )