Contexts

Contexts are expressions that control whether commands like update run certain changesets.You add contexts directly to changesets in your changelog and specify them at runtime using the --contexts attribute in the CLI. Context names are case-insensitive strings. A changeset can have up to one context, but you can specify several contexts in the CLI.

By default, a database update runs all changesets in the changelog, regardless of what you specify in the CLI. If you add a context to a changeset, it only runs when you specify that context in the CLI, but unmarked changesets still run. If you do not specify any contexts in the CLI at runtime, every changeset in your changelog runs, even if they have contexts attached.

Here are examples of SQL, XML, JSON, and YAML changesets using the context attribute:

--changeset bob:1 context:test
insert into news (id, title) values (1, 'Liquibase 0.8 Released')
<changeSet id="2" author="bob" context="test">
        <insert tableName="news">
            <column name="id" value="1"/>
            <column name="title" value="Liquibase 0.8 Released"/>
        </insert>
</changeSet>
{
    "changeSet": {
        "id": "2",
        "author": "bob",
        "context": "test",
        "changes": [
            {
                "insert": {
                    "tableName": "news",
                    "columns": [
                        {
                            "column": {
                                "name": "id",
                                "value": "1"
                            }
                        },
                        {
                            "column": {
                                "name": "title",
                                "value": "Liquibase 0.8 Released"
                            }
                        }
                    ]
                }
            }
        ]
    }
}
- changeSet:
    id: 2
    author: bob
    context: test
    changes:
      - insert:
          tableName: news
          columns:
            - column:
                name: id
                value: 1
            - column:
                name: title
                value: "Liquibase 0.8 Released"

Context syntax

You can specify a context using AND, OR, !, and parentheses in the changesets. Without parentheses, the order of operations is !, AND, and then OR.

Examples:

  • context="!test"
  • context="v1.0 or map"
  • context="!qa and !master"

Using a "," to separate contexts works like an OR operation but with the highest precedence.

Examples:

  • "test, qa" is the same as "test OR qa"
  • "test, qa and master" is the same as "(test) OR (qa and master)"

Availability:

  • "," separator is available in all versions of Liquibase
  • "AND, OR, !, parentheses" are added in 3.2.0

Running contexts

You can only specify context logic in a changeset definition, but you can still specify multiple contexts when running Liquibase in the CLI. However, you can only list out all the contexts that apply to the current Liquibase run.

liquibase --changelog-file=changelog.xml --contexts="test" update

If your changelog includes several changesets with complex and simple contexts such as context="qa and master and !dev" for changeset 1 and context="test" for changeset 2, you need to pass the following on the command line to deploy them:

liquibase --changelog-file=changelog.xml --contexts="test,qa,master" update

Using contexts for test data

If you manage your test data with Liquibase, it is best practice to have this data in line with all your other changesets, but marked with a "test" context. When you want your test data inserted, run a database update and specify the "test" context in the CLI. When you need to migrate your production database, don't include the "test" context, and your test data will not be included.

Note: If you do not specify any contexts in the CLI at runtime, every changeset will be applied, including those marked with a "test" context.

If you have multiple test environments or test data sets, simply tag them with different contexts, like "min-test" and "integration-test".

Using contexts to control test data is better than having a separate changelogs tree because later Change Types and changes will be applied to existing test data the same as they are applied to production data. If you had a set of test data that was created and simply added after the database is set up, you would be constantly manually updating your test data scripts to keep them in line with the current database schema.

Using contexts for multi-DBMS changelogs

You can use contexts to control which changesets are run on which databases, but there is an option to use the built in "dbms" tag on the changeset tag.

Default context

Starting with Liquibase 3.5, you can specify a context attribute in the root DATABASECHANGELOG node to assign that context to all changesets in the changelog by default.

The specified context will have AND with any contexts specified in changesets within the changelog file.

include and includeAll contexts

Starting with Liquibase 3.5, you can specify a context attribute in <include> or <includeAll> tags. If specified, the given context is added to all changesets in the included file(s).