diff-changelog

The diff-changelog command displays the differences between two databases you are comparing. It also generates a changelog file containing deployable changesets to resolve most of these differences.

Uses

The diff-changelog command is typically used when you want to create a deployable changelog to synchronize multiple databases. The diff-changelog command also provides more information about:

• Missing objects in your database
• Changes made to your database
• Unexpected items in your database

Running the diff-changelog command

Running the diff-changelog  command requires two URLs:

• referenceURL – the source for the comparison. The referenceUrl attribute represents your source (reference) database, which is the basis for the database you want to compare.
• url – the target of the comparison. The url attribute represents your target database, which you want to compare to the source (reference) database. You typically perform actions and run commands on this database.

To create a diff changelog:

• Option 1: Run the diff-changelog command with all necessary attributes in the CLI:

liquibase diff-changelog --changelog-file=example-changelog.xml 
--url="jdbc:oracle:thin:@<IP OR HOSTNAME>:<PORT>:<SERVICE NAME OR SID>"
--username=<USERNAME>
--password=<PASSWORD>
--referenceUrl="jdbc:oracle:thin:@<IP OR HOSTNAME>:<PORT>:<SERVICE NAME OR SID>"
--referenceUsername=<USERNAME>
--referencePassword=<PASSWORD>

Tip: For best results, specify all commands and parameters in the --kebab-case format in the CLI. If your preference is camelCase, it also works in the CLI.

See the snapshot command topic for an example of using a snapshot file as one of the databases being used in the command.

Tip: Liquibase recommends that you place your database's JDBC driver JAR file in the liquibase/lib directory. If you place the driver file in a different directory, specify the path in the properties file: classpath:../<path-to-drivers>/ojdbc<version>.jar. For more information, see Create and Configure a liquibase.properties File. When you run the diff command against two databases, either the drivers for both must be in the liquibase/lib directory or the classpath property must reference both JAR files. Use the appropriate path separator for your operating system: for Windows, use a semicolon; for Mac or Linux, use a colon.

Example: classpath: ojdbc7.jar:postgresql-42.2.8.jar

• Option 2: Configure the Liquibase properties file to include the connection information for both databases. Then, run the following command in the CLI:

liquibase diff-changelog --changelog-file=example-changelog.xml 

Note: If you specify a changelog file name that already exists, Liquibase will append your changes to the existing file.

For information, see Create and Configure a liquibase.properties File.

Output

The diff-changelog command produces a list of all objects and creates a changelog with a list of changesets.

Liquibase Open Source diff-changelog categories:

• Catalog
• Column
• Foreign Key
• Index
• Primary Key
• Schema
• Sequence
• Unique Constraints
• View

Filtering diff-changelog types

You can filter what objects diff-changelog generates with the diffTypes attribute:

--diffTypes=<catalogs,tables,functions,views,columns,indexes,foreignkeys,primarykeys,uniqueconstraints,storedprocedures,triggers,sequences,databasepackage,databasepackagebody>

You can also filter specific objects by name with the includeObjects and excludeObjects attributes. For example:

--includeObjects=table:tableName,column:columnName,view:viewName,index:indexName
--excludeObjects=table:tableName,column:columnName,view:viewName,index:indexName

This way, you can prevent any undesired objects from ending up in the resulting changelog.

Additional Functionality with Liquibase Pro

While Liquibase Open Source stores all changesets in a changelog, Liquibase Pro creates a directory called Objects and places the directory at the same level as your changelog. The Objects directory contains a subdirectory for each of the following stored logic types:

• checkconstraint
• package
• packagebody
• procedure
• function
• trigger
• synonyms

Note: Not all database platforms support all stored logic types that are listed.

The diff-changelog command structures stored logic files into timestamped directories every time you run the command.

Note: Liquibase does not currently check data type length.

Command arguments

Attribute	Definition	Requirement
--changelog-file	The root changelog	Required
--reference-url	The JDBC reference database connection URL	Required
--url	The JDBC database connection URL. See Using JDBC URL in Liquibase.	Required
--author	Specifies the author for changesets in the generated changelog.	Optional
--default-catalog-name	Name of the default catalog to use for the database connection	Optional
--default-schema-name	Name of the default schema to use for the database connection. If defaultSchemaName is set, then objects do not have to be fully qualified. This means you can refer to just mytable instead of myschema.mytable. Tip: In Liquibase v4.23.0+, camelCase for defaultSchemaName works successfully. If you are on an earlier version, camelCase may not work as expected. Note: The syntax liquibase.command.defaultSchemaName is valid for v4.19.0+. For prior versions, use defaultSchemaName.	Optional
--diff-types	Specifies the types of objects to compare. Includes a list of diff types in a changelog file expressed as a comma-separated list (without spaces): catalogs, tables, functions, views, columns, indexes, foreignkeys, primarykeys, uniqueconstraints, data, storedprocedures, triggers, sequences, databasepackage, databasepackagebody. If null, default types are tables, views, columns, indexes, foreignkeys, primarykeys, uniqueconstraints.	Optional
--driver	The JDBC driver class	Optional
--driver-properties-file	The JDBC driver properties file	Optional
--exclude-objects	Objects to exclude from diff	Optional
--include-catalog	If true, the catalog will be included in generated changesets. Default: false	Optional
--include-objects	Objects to include in diff	Optional
--include-schema	If true, the schema will be included in generated changesets. Default: false	Optional
--include-tablespace	Include the tablespace attribute in the changelog. Default: false	Optional
--output-schemas	Output schemas names. This is a CSV list.	Optional
--password	Password to connect to the target database. Tip: It is a best practice to store sensitive data in a Secrets Management tool with Liquibase Pro.	Optional
--reference-default-catalog-name	The reference default catalog name to use for the database connection	Optional
--reference-default-schema-name	The reference default schema name to use for the database connection	Optional
--reference-driver	The JDBC driver class for the reference database	Optional
--reference-driver-properties-file	The JDBC driver properties file for the reference database	Optional
--reference-password	The reference database password. Tip: It is a best practice to store sensitive data in a Secrets Management tool with Liquibase Pro.	Optional
--reference-schemas	Schemas names on reference database to use in diff. This is a CSV list.	Optional
--reference-username	The reference database username. Tip: It is a best practice to store sensitive data in a Secrets Management tool with Liquibase Pro.	Optional
--schemas	Schemas to include in diff	Optional
--username	Username to connect to the target database. Tip: It is a best practice to store sensitive data in a Secrets Management tool with Liquibase Pro.	Optional