Vlad Mihalcea,

I think the problem with Dialect.supportsIfExistsAfterConstraintName is the fact we generate an

ALTER TABLE  table_name DROP CONSTRAINT constraint_name IF EXISTS ...

that fails because the table does not exist.

Anyway I agree for consistency to have Dialect.supportsIfExistsAfterAlterTable(), the drop statement is already managed by Dialect.getDropTableString(String tableName)