class MetadataDao extends NamedParameterJdbcDaoSupport {

    public List<String> loadUniqueValuesFromEntitiesAttribute(final AclClass entityClass, final String attributeKey) {
        return getNamedParameterJdbcTemplate().query(loadUniqueValuesFromEntitiesAttributes,
                                       MetadataParameters.getParametersForEntityAndKey(entityClass, attributeKey),
                                       MetadataParameters.getUniqueAttributesExtractor());
    }

}