84 lines
2.4 KiB
PL/PgSQL
84 lines
2.4 KiB
PL/PgSQL
-- Add comment aggregates
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create table comment_aggregates (
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id serial primary key,
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comment_id int references comment on update cascade on delete cascade not null,
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score bigint not null default 0,
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upvotes bigint not null default 0,
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downvotes bigint not null default 0,
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published timestamp not null default now(),
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unique (comment_id)
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);
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insert into comment_aggregates (comment_id, score, upvotes, downvotes, published)
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select
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c.id,
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COALESCE(cl.total, 0::bigint) AS score,
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COALESCE(cl.up, 0::bigint) AS upvotes,
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COALESCE(cl.down, 0::bigint) AS downvotes,
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c.published
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from comment c
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left join ( select l.comment_id as id,
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sum(l.score) as total,
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count(
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case
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when l.score = 1 then 1
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else null::integer
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end) as up,
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count(
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case
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when l.score = '-1'::integer then 1
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else null::integer
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end) as down
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from comment_like l
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group by l.comment_id) cl on cl.id = c.id;
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-- Add comment aggregate triggers
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-- initial comment add
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create function comment_aggregates_comment()
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returns trigger language plpgsql
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as $$
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begin
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IF (TG_OP = 'INSERT') THEN
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insert into comment_aggregates (comment_id) values (NEW.id);
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ELSIF (TG_OP = 'DELETE') THEN
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delete from comment_aggregates where comment_id = OLD.id;
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END IF;
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return null;
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end $$;
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create trigger comment_aggregates_comment
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after insert or delete on comment
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for each row
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execute procedure comment_aggregates_comment();
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-- comment score
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create function comment_aggregates_score()
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returns trigger language plpgsql
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as $$
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begin
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IF (TG_OP = 'INSERT') THEN
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update comment_aggregates ca
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set score = score + NEW.score,
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upvotes = case when NEW.score = 1 then upvotes + 1 else upvotes end,
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downvotes = case when NEW.score = -1 then downvotes + 1 else downvotes end
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where ca.comment_id = NEW.comment_id;
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ELSIF (TG_OP = 'DELETE') THEN
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-- Join to comment because that comment may not exist anymore
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update comment_aggregates ca
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set score = score - OLD.score,
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upvotes = case when OLD.score = 1 then upvotes - 1 else upvotes end,
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downvotes = case when OLD.score = -1 then downvotes - 1 else downvotes end
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from comment c
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where ca.comment_id = c.id
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and ca.comment_id = OLD.comment_id;
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END IF;
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return null;
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end $$;
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create trigger comment_aggregates_score
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after insert or delete on comment_like
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for each row
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execute procedure comment_aggregates_score();
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