createIndex

createIndex is a Change Type in the Liquibase Open Source and Liquibase Pro extensions for MongoDB that creates an index on a collection.

Uses

The Liquibase Pro extension for MongoDB includes several modeled Change Types from the Liquibase Open Source version. These let you specify a few MongoDB commands using Liquibase XML, JSON, and YAML changelogs.

createIndex is one such Change Type. You can use it to create an index on an existing collection in your database. This can help you run efficient queries on data that would otherwise be expensive to retrieve.

Note: If you want to specify mongosh statements in your XML, JSON, and YAML changelogs, use the mongo and mongoFile Change Types instead.

Run

To run this Change Type, follow these steps:

1. Add the Change Type to your changeset, as shown in the examples on this page.
2. Specify any required attributes. Use the table on this page to see which ones your database requires.
3. Deploy your changeset by running the update command:

liquibase update

Available attributes

For more information, see db.collection.createIndex().

Tip: You must specify all top-level attributes marked as required. If you specify an optional attribute, you must also specify any nested attributes that it requires.

keys

Required. A document that defines the index's basic contents and structure.

keys has the following nested attributes:

• name (required): the name of a key in the collection to use for the index
• type (required): the type of the index. For an ascending index, specify 1. For a descending index, specify -1. Other accepted values include text, geospatial, hashed, and more.

options

Optional. A document that defines additional features for the index.

options has the following nested attributes:

• unique (optional): if true, creates a unique index so that the collection will not accept insertion or update of documents where the index key value matches an existing value in the index. Default: false.
• name (optional): the name of the index. If unspecified, MongoDB generates an index name by concatenating the names of the indexed fields and the sort order.

Examples

<databaseChangeLog
    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mongodb="http://www.liquibase.org/xml/ns/mongodb"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
    http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
    http://www.liquibase.org/xml/ns/mongodb
    http://www.liquibase.org/xml/ns/mongodb/liquibase-mongodb-latest.xsd">

    <changeSet id="3" author="your.name">
        <mongodb:createIndex collectionName="countries">
            <mongodb:keys>
                { name: 1, type: 1}
            </mongodb:keys>
            <mongodb:options>
                {unique: true, name: "ui_countries"}
            </mongodb:options>
        </mongodb:createIndex>
    </changeSet>

</databaseChangeLog>

databaseChangeLog:
  - changeSet:
      id: 3
      author: your.name
      changes:
        - createIndex:
            collectionName: countries_yaml
            keys: '{ name: 1, type: 1}'
            options: '{unique: true, name: "ui_countries"}'

{
  "databaseChangeLog": [
    {
      "changeSet": {
        "id": "3",
        "author": "your.name",
        "changes": [
          {
            "createIndex": {
              "collectionName": "countries_json",
              "keys": {
                "$rawJson": {
                  "name": 1,
                  "type": 1
                }
              },
              "options": {
                "$rawJson": {
                  "unique": true,
                  "name": "ui_countries_json"
                }
              }
            }
          }
        ]
      }
    }
  ]
}

Database support

This Change Type is only supported for MongoDB. It does not support auto rollback.