- Liquibase expects the scemea to be modeled in its schema language. This makes it possible to compute changes between the database and the new schema and apply those changes, or to just create old-fashioned migration scripts.
- Th. Doctrine and Hibernate ORMs can do similar things.
- Flyway expects developers to write migrations by themselves, either in Java or in SQL, and just executes them and records state information. It's not too bad to write migrations yourself because the data you work with is usually valuable.
Yes, they can do similar things. However, there are several cases which you cannot handle automatically, due to incomplete information:
- The current schema has a column A and the new version does not have A but a similar column B. Is this a new column? Or should A be renamed into B? (same for renaming tables)
- You add a new table A which contains columns from B, which are also removed from B. Should this data be copied?
- You change the structure of a table, and have some of it split off into different tables. How does the schema tool know how to rearrange the current data?
There are probably some more cases, but these are the ones I could think of quickly.
- Th. Doctrine and Hibernate ORMs can do similar things.
- Flyway expects developers to write migrations by themselves, either in Java or in SQL, and just executes them and records state information. It's not too bad to write migrations yourself because the data you work with is usually valuable.