Chado database and SQL queries

Question

[onemore100iq]

How to write SQL query to get polypeptide/protein features from Chado database to show the bifunctional proteins and the fmin, fmax and strand coordinates.

This is what I wrote and did not work:

SELECT f.uniquename, product.value 
FROM feature f 
JOIN cvterm polypeptide ON f.type_id=polypeptide.cvterm_id 
JOIN featureprop product ON f.feature_id=product.feature_id 
JOIN cvterm productprop ON product.type_id=productprop.cvterm_id 
WHERE polypeptide.name = 'polypeptide' 
AND productprop.name = 'gene_product_name';