How to use

SchemaChanges

in

leap.db.change

/**
 * Returns the add only changes (no update and remove).
 */
default SchemaChanges addOnly() {
  return filter((c) -> c.isAdd());
}

protected boolean upgradeTable(EntityMapping em, DbTable exists) {
  SchemaChanges changes = 
      db.getComparator().compareTable(em.getTable(), exists)
       .addOnly();
  if(changes.isEmpty()) {
    return true;
  }
  
  upgradeTableExecution = changes.applyChanges();
  return upgradeTableExecution.success();
}

for(SchemaChanges changes : allChanges){
  DbCommands changeCommands = changes.filter(changePredicate)
                    .process(changeProcessor)
                    .getChangeCommands();