MySQL server has gone away
SELECT pot.*, povt.*, v.option_value_ru as variantName
FROM SC_product_options_values as povt
LEFT JOIN SC_products_opt_val_variants as v ON v.variantID=povt.variantID
LEFT JOIN SC_product_options as pot ON pot.optionID=povt.optionID
WHERE povt.productID IN ('29558')
GROUP BY povt.optionID
ORDER BY pot.sort_order, pot.name_ru