So!, I was/am writing a subquery to get a value to rating_stars… and I got this (beginner) error…
mysql – #1241 – Operand should contain 1 column(s)
(SELECT value, (sum(value)/count(value)) FROM model_ratings WHERE modelId = id) AS rating_stars
Subquery should return one column, whatever corresponds to rating_stars.
(...) (SELECT (sum(value)/count(value)) FROM model_ratings WHERE modelId = id) AS rating_stars (...)