db.collection.dropIndex()

Definition定义

db.collection.dropIndex(index)

Important重要

mongosh Method

This is a mongosh method. This is not the documentation for Node.js or other programming language specific driver methods.

In most cases, mongosh methods work the same way as the legacy mongo shell methods. However, some legacy methods are unavailable in mongosh.

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

• mongo shell v4.4
• mongo shell v4.2
• mongo shell v4.0

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

Drops or removes the specified index from a collection. 从集合中删除或移除指定的索引。The db.collection.dropIndex() method provides a wrapper around the dropIndexes command.db.collection.dropIndex()方法提供了dropIndexes命令的包装。

Note注意

• 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，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()。

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	Optional. 可选。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.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，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.在版本4.4中新增。 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()的索引仍在构建中，db.collection.dropIndex()会尝试停止正在进行的构建。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，db.collection.dropIndex()将返回错误。See Stop In-Progress Index Builds for more complete documentation.有关更完整的文档，请参阅停止进行中索引生成。

To get the index name or the index specification document for the db.collection.dropIndex() method, use the db.collection.getIndexes() method.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。

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，在进行索引生成期间尝试删除其他索引会导致BackgroundOperationInProgressForNamespace错误。

Example示例

Consider a pets collection. 考虑集合pets。Calling the db.collection.getIndexes() method on the pets collection returns the following indexes: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，可以使用索引名称：

db.pets.dropIndex( "catIdx" )

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

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