generate-changelog

The generate-changelog command creates a changelog file that has a sequence of changesets which describe how to re-create the current state of the database.


Uses

The generate-changelog command is typically used when you want to capture the current state of a database, then apply those changes to any number of databases. This is typically only done when a project has an existing database, but hasn't used Liquibase before. See How to set up Liquibase with an Existing Project and Multiple Environments for more details.

Note: When using the update command to apply the changes in the changelog, Liquibase will not create a new database or schema. You must create them before applying the changelog to it.

Run the generate-changelog command

In this example, our sample database has the following content:

To generate a changelog from our sample database:

  1. Configure the Liquibase properties file to include your driver, classpath, and URL for the database you want to capture. Alternatively, you can pass the necessary information as environment variables or from the command line.
  2. Decide which data types you want to include. You can specify these with the --diff-types parameter.
  3. Open your CLI and run one of the following commands:
    • Generate a changelog without specifying diff types (Liquibase uses the default diff types: columns, foreignkeys, indexes, primarykeys, tables, uniqueconstraints, and views):
      • liquibase generate-changelog --changelog-file=example-changelog.xml
    • Generate a changelog with specific diff types:
      • liquibase generate-changelog --changelog-file=example-changelog.xml --diff-types=catalogs,checkconstraints,columns,databasepackage,databasepackagebody,foreignkeys,functions,indexes,primarykeys,sequences,storedprocedures,tables,triggers,uniqueconstraints,views

Liquibase then generates your changelog and displays the following message:

BEST PRACTICE: The changelog generated by diffChangeLog/generateChangeLog should be inspected for correctness and completeness before being deployed. Some database objects and their dependencies cannot be represented automatically, and they may need to be manually updated before being deployed.
Generated changelog written to example-changelog.xml
Liquibase command 'generate-changelog' was executed successfully.

Output changelogs

The generate-changelog command generates a changelog that contains all your objects (represented as changesets) and places the file in the same directory where the command was ran.

The extension you provide determines the format of the changelog, so if you specify the filename as changelog.xml, you will get an XML formatted changelog. However, if you specify the filename as changelog.yaml, changelog.json, or changelog.sql, you will get changelogs formatted in YAML, JSON, or SQL, respectively.

Note: By default, Liquibase does not split statements for formatted SQL changelogs because splitStatements is set to false in the changelog. If the generatedSQL has multiple SQL statements, then Liquibase adds splitStatements:true to the changelog.

Learn more about split statements here: sql

Default diff types

<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:pro="http://www.liquibase.org/xml/ns/pro"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
    http://www.liquibase.org/xml/ns/pro http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd
    http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd">
    <changeSet author="tfernandez (generated)" id="1704821089427-1">
        <createTable tableName="testtable">
            <column defaultValue="My text value" name="text" type="VARCHAR" />
            <column autoIncrement="true" name="number" type="INTEGER">
                <constraints nullable="false" />
            </column>
            <column name="date" type="date">
                <constraints nullable="false" />
            </column>
        </createTable>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-2">
        <pro:createFunction functionName="customfunction"
            path="objects/function/customfunction-bcd8b0c2.sql" relativeToChangelogFile="true" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-3">
        <createTable tableName="foreigntable">
            <column autoIncrement="true" name="id" type="INTEGER">
                <constraints nullable="false" />
            </column>
            <column name="foreignid" type="INTEGER">
                <constraints nullable="false" />
            </column>
        </createTable>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-4">
        <pro:createTrigger disabled="false"
            path="objects/trigger/testtable_customtrigger-41365cf7.sql"
            relativeToChangelogFile="true" tableName="testtable" triggerName="customtrigger" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-5">
        <addUniqueConstraint columnNames="number" constraintName="testtable_un"
            tableName="testtable" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-6">
        <createView fullDefinition="false" viewName="customview">SELECT id,
            foreignid
            FROM foreigntable;
        </createView>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-7">
        <createProcedure path="objects/storedprocedure/customProcedure.sql"
            procedureName="customProcedure" relativeToChangelogFile="true" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821089427-8">
        <addForeignKeyConstraint baseColumnNames="foreignid" baseTableName="foreigntable"
            constraintName="fk_foreigntable" deferrable="false" initiallyDeferred="false"
            onDelete="NO ACTION" onUpdate="NO ACTION" referencedColumnNames="number"
            referencedTableName="testtable" validate="true" />
    </changeSet>
</databaseChangeLog>

Specific diff types

<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:pro="http://www.liquibase.org/xml/ns/pro"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
    http://www.liquibase.org/xml/ns/pro http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd
    http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd">
    <changeSet author="tfernandez (generated)" id="1704821340603-1">
        <createTable tableName="testtable">
            <column defaultValue="My text value" name="text" type="VARCHAR" />
            <column autoIncrement="true" name="number" type="INTEGER">
                <constraints nullable="false" />
            </column>
            <column name="date" type="date">
                <constraints nullable="false" />
            </column>
        </createTable>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-2">
        <insert tableName="testtable">
            <column name="text" value="one" />
            <column name="number" valueNumeric="1" />
            <column name="date" valueDate="2024-01-09" />
        </insert>
        <insert tableName="testtable">
            <column name="text" value="three" />
            <column name="number" valueNumeric="2" />
            <column name="date" valueDate="2024-01-09" />
        </insert>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-3">
        <pro:createFunction functionName="customfunction"
            path="objects/function/customfunction-bcd8b0c2.sql" relativeToChangelogFile="true" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-4">
        <createTable tableName="foreigntable">
            <column autoIncrement="true" name="id" type="INTEGER">
                <constraints nullable="false" />
            </column>
            <column name="foreignid" type="INTEGER">
                <constraints nullable="false" />
            </column>
        </createTable>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704822563807-1">
        <pro:addCheckConstraint constraintName="testtable_check" disabled="false" tableName="testtable">
            ((number > 0))
        </pro:addCheckConstraint>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-5">
        <pro:createTrigger disabled="false"
            path="objects/trigger/testtable_customtrigger-41365cf7.sql"
            relativeToChangelogFile="true" tableName="testtable" triggerName="customtrigger" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-6">
        <addUniqueConstraint columnNames="number" constraintName="testtable_un"
            tableName="testtable" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-7">
        <createView fullDefinition="false" viewName="customview">SELECT id,
            foreignid
            FROM foreigntable;
        </createView>
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-8">
        <addForeignKeyConstraint baseColumnNames="foreignid" baseTableName="foreigntable"
            constraintName="fk_foreigntable" deferrable="false" initiallyDeferred="false"
            onDelete="NO ACTION" onUpdate="NO ACTION" referencedColumnNames="number"
            referencedTableName="testtable" validate="true" />
    </changeSet>
    <changeSet author="tfernandez (generated)" id="1704821340603-9">
        <createProcedure path="objects/storedprocedure/customProcedure.sql"
            procedureName="customProcedure" relativeToChangelogFile="true" />
    </changeSet>
</databaseChangeLog>

Parameters

Global parameters

Attribute Definition Requirement

--license-key=<string>

Your Liquibase Pro license key

 Required

Command parameters

Attribute Definition Requirement

--url=<string>

The JDBC database connection URL. See Using JDBC URL in Liquibase.

 Required

--author=<string>

Specifies the author for changesets in the generated changelog.

 Optional

--changelog-file=<string>

Changelog file to write results

 Optional

--context-filter=<string>

Specifies the context filter to generate and apply to all changesets in your changelog. Useful to set many contexts quickly. Similar to the set-contexts command. Available in Liquibase 4.24.0 and later.

Contexts are tags you can add to changesets to control which changesets will be executed in any particular migration run.

After generating changesets with contexts, to deploy specific changes according to these contexts, you must run a command that specifies a context filter. For example, update --context-filter=<xyz>.

 Optional

--data-output-directory=<string>

Specifies a directory to send the loadData output to a CSV file which is generated by running the diff-changelog or generate-changelog command.

 Optional

--default-catalog-name=<string>

Name of the default catalog to use for the database connection

 Optional

--default-schema-name=<string>

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.

Note: In the properties file and JAVA_OPTS only: in 4.18.0 and earlier, specify this parameter using the syntax defaultSchemaName. In 4.19.0 and later, use the syntax liquibase.command.defaultSchemaName.

Note: In Liquibase 4.12.0 and later, you can use mixed-case schema names if you set --preserve-schema-case to true. However, in Liquibase 4.12.0–4.22.0, the Liquibase validator still throws a DatabaseException error if you specify a mixed-case value of defaultSchemaName. In 4.23.0 and later, the Liquibase validator accepts any casing.

 Optional

--diff-types=<string>

Specifies the types of objects to compare. Specify multiple values as a comma-separated list (without spaces). Valid values are: catalogs, checkconstraints, columns, data, databasepackage, databasepackagebody, foreignkeys, functions, indexes, primarykeys, sequences, storedprocedures, tables, triggers, uniqueconstraints, views.

If null, default types are columns, foreignkeys, indexes, primarykeys, tables, uniqueconstraints, views.

Note: The diff types checkconstraints, databasepackage, databasepackagebody, functions, storedprocedures, and triggers require a valid Liquibase Pro license key to use.

 Optional

--driver=<string>

The JDBC driver class

 Optional

--driver-properties-file=<string>

The JDBC driver properties file

 Optional

--exclude-objects=<string>

Objects to exclude from diff

 Optional

--include-catalog=<true|false>

If true, the catalog will be included in generated changesets. Default: false

 Optional

--include-objects=<string>

Objects to include in diff

 Optional

--include-schema=<true|false>

If true, the schema will be included in generated changesets. Default: false

 Optional

--include-tablespace=<true|false>

Includes the tablespace of tables and indexes in a generated changesets if the value is true. The default value is false.

 Optional *

--label-filter=<string>

Specifies the label filter to generate and apply to all changesets in your changelog. Useful to set many labels quickly. Similar to the set-labels command. Available in Liquibase 4.24.0 and later.

Labels are tags you can add to changesets to control which changeset will be executed in any migration run.

After generating changesets with labels, to deploy specific changes according to these labels, you must run a command that specifies a label filter. For example, update --label-filter=<xyz>.

 Optional

--output-schemas=<string>

Lets you replace the schemas in the output changelog. This is a CSV list. The parameter size must match --schemas. If you have three items names in --schemas, you must also have three items in --output-schemas.

Example: liquibase generate-changelog --schemas=a,b,c --output-schemas=d,e,f

Optional

--overwrite-output-file=<true|false>

Determines whether generate-changelog can overwrite an existing changelog, including one specified in --changelog-file. Default: false.

 Optional

--password=<string>

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

--preserve-null-values=<string>

If true, column nodes will be created with null values. For example:

<insert schemaName="public" tableName="liquibase_rules">

<column name="a" value="AA" />

<column name="b" value="null" />

<column name="c" value="null" />

</insert>

If false, null values will be ignored. For example:

<insert schemaName="public" tableName="liquibase_rules">

<column name="a" value="AA" />

</insert>

Optional

--replace-if-exists-types=<string>

Specify Change Types you want to target. Liquibase sets replaceIfExists="true" on these Change Types: createFunction, createPackage, createPackageBody, createProcedure, createTrigger, and createView. Liquibase 4.26.0+. Default: <none>.

 Optional

--run-on-change-types=<string>

Specify Change Types you want to target. Liquibase sets runOnChange="true" on changesets containing solely these Change Types: createFunction, createPackage, createPackageBody, createProcedure, createTrigger, and createView. Liquibase 4.26.0+. Default: <none>.

 Optional

--schemas=<string>

Specifies database schemas you want to include

 Optional

--skip-object-sorting=<true|false>

Liquibase 4.27.0+. Specifies how Liquibase sorts a list of objects in your database to generate a changelog. When true, Liquibase skips object sorting, so your objects are sorted according to the order returned by your database. This can be useful on databases that have a lot of packages or procedures that are linked to each other. When false, Liquibase sorts objects by dependency. This may avoid dependency errors. Default: false.

Note: If you set this parameter to true, Liquibase may create objects in the wrong order (such as a view on a table before the table itself), so you may have to manually reorganize the generated changelog file.

 Optional

--username=<string>

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

Note: The username and password attributes are not required for connections and systems which use alternate means of authentication. Also, you can specify database credentials as part of the url attribute.

* --include-tablespace only captures the tablespace if it was specified in the create table statement.

Database objects supported by Liquibase

You can use the following object types in Liquibase:

Object type --diff-types syntax Liquibase edition
Catalog catalogs Liquibase Open Source
Column columns Liquibase Open Source
Data data Liquibase Open Source
Foreign key foreignkeys Liquibase Open Source
Index indexes Liquibase Open Source
NOT NULL constraint N/A Liquibase Open Source
Primary key primarykeys Liquibase Open Source
Schema N/A Liquibase Open Source
Sequence sequences Liquibase Open Source
Table tables Liquibase Open Source
Unique constraint uniqueconstraints Liquibase Open Source
View views Liquibase Open Source
Check constraint checkconstraints Liquibase Pro
Function functions Liquibase Pro
Package databasepackage Liquibase Pro
Package body databasepackagebody Liquibase Pro
Stored procedure storedprocedures Liquibase Pro
Trigger triggers Liquibase Pro

Liquibase Pro stored logic behavior

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 subdirectories for each of the stored logic types:

  • package
  • packagebody
  • function
  • stored procedure
  • trigger

Note: Some database platforms may not support all of these stored logic types.

The generate-changelog command will not create the Objects directory if:

  • You don't have a valid Liquibase Pro license key.
  • Stored logic is not present in the database.
  • The target database does not support the generate-changelog command and stored logic objects.
  • The changelog file is written in formatted SQL. The Objects folder can only be created when generating XML, JSON, or YAML changelogs.
  • There is a pre-existing directory called Objects that was created outside Liquibase.

If your database contains Stored Logic objects, you may have issues attempting to run the generate-changelog command more than once, even with a new changelog name, because the stored logic files already exist in the Objects directory.

To generate a newer version of the changelog file with stored logic objects based on the current database state, you need to delete, rename, or move the Objects directory that was created by running the generate-changelog command previously. Then, you can run the generate-changelog command again.

Note: If there is a pre-existing Objects directory that is not related to Liquibase, you need to delete, rename, or move it to run the generate-changelog command.

If you want to track the history of stored logic objects, use the diff-changelog command. The diff-changelog command structures stored logic files into timestamped directories every time you run the command.

Related links