What's wrong with this query?
SELECT ps_stock_available.quantity
FROM ps_stock_available
INNER JOIN ps_product_attribute ON ps_product_attribute.id_product ON ps_stock_available.id_product
WHERE ps_product_attribute.reference =100102
I think you intend:
SELECT sa.quantity
FROM ps_stock_available sa INNER JOIN
ps_product_attribute pa
ON sa.id_product = pa.id_product
WHERE pa.reference = 100102;
Notes:
ON
clause contains a boolean expression.JOIN
has a single ON
clause.