Overview

Ebean has the ability to generate and execute CREATE ALL and DROP ALL DDL scripts which create all the tables. These are typically used when running tests and frequently these tests run against H2 database rather than the target Postgres/Oracle/MySql/SQL Server ... database. That is, when running a test or suite of tests the DB is created entirely from scratch.

When running a test or suite of tests the DB is created entirely from scratch

test-ebean.properties

Usually you set both ebean.ddl.generate and ebean.ddl.run to true in the test-ebean.properties (which is in src/test/resources) and in this way the CREATE ALL DDL is only generated and executed when running tests. 

ebean.ddl.generate=true
ebean.ddl.run=true

DB Migration

DB Migration is different in that DIFF DDL scripts are generated for the changes to the model and these DIFF DDL scripts can be applied to the target Postgres/Oracle/MySql/SQL Server ... database and often FlywayDb or Liquibase is used to apply those DDL changes.