sql_query CASE

SELECT
    name,
    AVG(weight::INTEGER) AS avg_weight
    CASE WHEN avg_weight = 72 AND units IS NULL THEN
        '%'
    CASE WHEN avg_weight = 1 AND units IS NULL THEN
        'кг'
    CASE WHEN avg_weight = 1  AND units IS NULL THEN
        'л'
    CASE WHEN avg_weight = 805 AND units IS NULL THEN
        'мл'
    CASE WHEN avg_weight = 402 AND units IS NULL THEN
        'г'
    ELSE
        units
    END AS weight_info;
FROM
    products;