update command

The update command deploys any changes that are in the changelog file and that have not been deployed to your database yet.

Uses

The update command is typically used to apply database changes that are specified in the changelog file to your database.

When you run the update command, Liquibase sequentially reads changesets in the changelog file, then it compares the unique identifiers of id, author, and path to filename to the values stored in the DATABASECHANGELOG table.

• If the unique identifiers do not exist, Liquibase will apply the changeset to the database.
• If the unique identifiers exist, the MD5Sum of the changeset is compared to the one in the database.
• If they are different, Liquibase will produce an error message that someone has changed it unexpectedly. However, if the status of the runOnChange or runAlways changeset attribute is set to TRUE, Liquibase will re-apply the changeset.

Running the update command

To run the update command, you need to specify your driver, class path, and URL in your liquibase.properties file. For more information, see Creating and configuring a liquibase.properties file. You can also specify these properties in your command line.

Then run the update command:

liquibase --changeLogFile=dbchangelog.xml update

Note: Enter the name of the changelog you want to use in place of dbchangelog.xml.

update global attributes

Attributes	Definition	Requirement
--changeLogFile	Specifies the root changelog	Required
--url	Specifies the JDBC database connection URL	Required
--username	Specifies the database username	Required
--password	Specifies the database password	Required

update command attributes

Attributes	Definition	Requirement
--labels	Tags you can add to changesets to determine which changesets in the changelog to evaluate based on their labels	Optional
--contexts	Expressions you can add to changesets to determine which changesets in the changelog to evaluate based on their contexts	Optional
--liquibaseSchemaName	Specifies in what Schema the Liquibase DATABASECHANGELOG and DATABASECHANGELOGLOCK tables will be managed	Optional
--liquibaseCatalogName	For MSSQL only: Specifies in what Catalog the Liquibase DATABASECHANGELOG and DATABASECHANGELOGLOCK tables will be managed	Optional