SELECT ov.option_value, ov.option_type, ov.variantID, v.option_value variant_value 
 FROM `ss_product_options_values` ov 
 LEFT JOIN `ss_products_opt_val_variants` v ON ov.variantID = v.variantID
 LEFT JOIN ss_products p ON ov.productID = p.productID AND p.categoryID IN (326) AND p.firmID IN (325,318,140,101,338,39,281,284,119)
 WHERE 1
 AND ov.optionID = '28' AND p.productID IN (6543,6544,5370,5372,6992,6993,11126,14271,14273,14269,14270,14272,15966,15967,15968,16933,16934,23014,23015,23016,23017,23018,23019,23021,23024,26847,28897) 
 AND 
 (
 (ov.option_type = 0 AND ov.option_value <> '') || 
 (ov.option_type = 1 AND v.option_value <> '')
 )
 -- AND ov.variantID IS NOT NULL
 GROUP BY ov.option_value, ov.option_type, ov.variantID, v.option_value