stacker.news/prisma/migrations/20230506233136_denorm_upvotes/migration.sql

42 lines
1.3 KiB
PL/PgSQL

-- AlterTable
ALTER TABLE "Item" ADD COLUMN "upvotes" INTEGER NOT NULL DEFAULT 0;
UPDATE "Item"
SET upvotes = subquery.votes
FROM (SELECT "ItemAct"."itemId", COUNT(DISTINCT "userId") AS votes
FROM "ItemAct"
WHERE "ItemAct".act = 'TIP'
GROUP BY "ItemAct"."itemId") subquery
WHERE "Item".id = subquery."itemId";
CREATE OR REPLACE FUNCTION weighted_votes_after_tip(item_id INTEGER, user_id INTEGER, sats INTEGER) RETURNS INTEGER AS $$
DECLARE
user_trust DOUBLE PRECISION;
sats_past INTEGER;
vote_add INTEGER := 0;
multiplier DOUBLE PRECISION;
BEGIN
-- grab user's trust who is upvoting
SELECT trust INTO user_trust FROM users WHERE id = user_id;
-- in order to add this to weightedVotes, we need to do log((satsN+satsPrior)/satsPrior)
-- so compute sats prior
SELECT SUM(msats) / 1000 INTO sats_past
FROM "ItemAct"
WHERE "userId" = user_id AND "itemId" = item_id AND act IN ('TIP', 'FEE');
IF sats_past IS NULL OR sats_past = 0 THEN
multiplier := LOG(sats);
vote_add := 1;
ELSE
multiplier := LOG((sats+sats_past)/sats_past::FLOAT);
END IF;
-- update item
UPDATE "Item"
SET "weightedVotes" = "weightedVotes" + (user_trust * multiplier), upvotes = upvotes + vote_add
WHERE id = item_id AND "userId" <> user_id;
RETURN 0;
END;
$$ LANGUAGE plpgsql;