Question

We would like to use H2 in-memory database for automated testing of our web-applications.
We use Oracle 10 for our production and development environments.

So the idea is to duplicate the table structure in H2 test-database as it is in our Oracle dev-database.

It there an easy way to extract DDLs from an Oracle 10 schema (tables and constraints) so they could be executed against H2 database?

Answer 1

This script helped me:

create or replace function mymetadata return sys.ku$_ddls is
  md_handle number;
  tr_handle number;
  dl_handle number;

  result_array sys.ku$_ddls;
begin

  md_handle := dbms_metadata.open('TABLE');

  tr_handle := dbms_metadata.add_transform(md_handle, 'MODIFY');
  dbms_metadata.set_remap_param(tr_handle, 'REMAP_SCHEMA', 'MLIS_DEV', null);

  dl_handle := dbms_metadata.add_transform(md_handle, 'DDL');
  dbms_metadata.set_transform_param(dl_handle, 'SEGMENT_ATTRIBUTES', false);
  dbms_metadata.set_transform_param(dl_handle, 'STORAGE', false);
  dbms_metadata.set_transform_param(dl_handle, 'TABLESPACE', false);
  dbms_metadata.set_transform_param(dl_handle, 'REF_CONSTRAINTS', false);
  dbms_metadata.set_transform_param(dl_handle, 'SQLTERMINATOR', true);
  dbms_metadata.set_transform_param(dl_handle, 'CONSTRAINTS_AS_ALTER', true);

  LOOP
      result_array := dbms_metadata.fetch_ddl(md_handle);
      EXIT WHEN result_array IS NULL;

      FOR i IN result_array.FIRST..result_array.LAST LOOP
          dbms_output.put_line(result_array(i).ddltext);
      END LOOP;
  END LOOP;    

  dbms_metadata.close(md_handle);


  md_handle := dbms_metadata.open('REF_CONSTRAINT');

  tr_handle := dbms_metadata.add_transform(md_handle, 'MODIFY');
  dbms_metadata.set_remap_param(tr_handle, 'REMAP_SCHEMA', 'MLIS_DEV', null);

  dl_handle := dbms_metadata.add_transform(md_handle, 'DDL');
  dbms_metadata.set_transform_param(dl_handle, 'SQLTERMINATOR', true);

  LOOP
      result_array := dbms_metadata.fetch_ddl(md_handle);
      EXIT WHEN result_array IS NULL;

      FOR i IN result_array.FIRST..result_array.LAST LOOP
          dbms_output.put_line(result_array(i).ddltext);
      END LOOP;
  END LOOP;    

  dbms_metadata.close(md_handle);

  return result_array;
end;
/


select ddltext from table(mymetadata);