stacker.news/prisma/migrations/20220224205443_run_auction/migration.sql

ALTER TABLE "Item" RENAME COLUMN "noSatsAt" TO "statusUpdatedAt";

-- charge the user for the auction item
CREATE OR REPLACE FUNCTION run_auction(item_id INTEGER) RETURNS void AS $$
    DECLARE
        bid INTEGER;
        user_id INTEGER;
        user_msats INTEGER;
        item_status "Status";
    BEGIN
        PERFORM ASSERT_SERIALIZED();

        -- extract data we need
        SELECT ("maxBid" * 5 / 216), "userId", status INTO bid, user_id, item_status FROM "Item" WHERE id = item_id;
        SELECT msats INTO user_msats FROM users WHERE id = user_id;

        -- check if user wallet has enough sats
        IF bid > user_msats THEN
            -- if not, set status = NOSATS and statusUpdatedAt to now_utc if not already set
            IF item_status <> 'NOSATS' THEN
                UPDATE "Item" SET status = 'NOSATS', "statusUpdatedAt" = now_utc() WHERE id = item_id;
            END IF;
        ELSE
            -- if so, deduct from user
            UPDATE users SET msats = msats - bid WHERE id = user_id;
            -- update item status = ACTIVE and statusUpdatedAt = null if NOSATS
            IF item_status = 'NOSATS' THEN
                UPDATE "Item" SET status = 'ACTIVE', "statusUpdatedAt" = now_utc() WHERE id = item_id;
            END IF;
        END IF;
    END;
$$ LANGUAGE plpgsql;