def freeze(h, output_yaml, resolve, groups):
    """Output installed packages."""
    if not groups:
        groups = filter(lambda group: not group.lower().startswith("bower"),
                        h.requirements.keys())
    else:
        groups = [text_type.strip(group) for group in groups.split(",")]

    if output_yaml:
        for requirements in h.requirements.values():
            for requirement in requirements:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
        click.echo(h.requirements.yaml)
    else:
        for group in groups:
            if not h.requirements[group]:
                continue
            click.echo("# {}".format(group))
            for requirement in h.requirements[group]:
                if resolve and not requirement.version:
                    requirement.load_installed_version()
                click.echo(str(requirement))
def _db_schema_sanity_check(engine):
    """Ensure all database tables were created with required parameters.

    :param engine:  SQLAlchemy engine instance for a given database

    """

    if engine.name == 'mysql':
        onlyutf8_sql = ('SELECT TABLE_NAME,TABLE_COLLATION '
                        'from information_schema.TABLES '
                        'where TABLE_SCHEMA=%s and '
                        'TABLE_COLLATION NOT LIKE "%%utf8%%"')

        table_names = [res[0] for res in engine.execute(onlyutf8_sql,
                                                        engine.url.database)]
        if len(table_names) > 0:
            raise ValueError(_('Tables "%s" have non utf8 collation, '
                               'please make sure all tables are CHARSET=utf8'
                               ) % ','.join(table_names))