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5f64fd0a21
Introduce new patterns for direct sql that are safe and fast. MiniSql is not prone to memory bloat that can happen with direct PG usage. It also has an extremely fast materializer and very a convenient API - DB.exec(sql, *params) => runs sql returns row count - DB.query(sql, *params) => runs sql returns usable objects (not a hash) - DB.query_hash(sql, *params) => runs sql returns an array of hashes - DB.query_single(sql, *params) => runs sql and returns a flat one dimensional array - DB.build(sql) => returns a sql builder See more at: https://github.com/discourse/mini_sql
92 lines
2.4 KiB
Ruby
92 lines
2.4 KiB
Ruby
class TopicFeaturedUsers
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attr_reader :topic
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def initialize(topic)
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@topic = topic
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end
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def self.count
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4
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end
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# Chooses which topic users to feature
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def choose(args = {})
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self.class.ensure_consistency!(topic.id.to_i)
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update_participant_count
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end
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def user_ids
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[topic.featured_user1_id,
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topic.featured_user2_id,
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topic.featured_user3_id,
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topic.featured_user4_id].uniq.compact
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end
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def self.ensure_consistency!(topic_id = nil)
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filter = "#{"AND t.id = #{topic_id.to_i}" if topic_id}"
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filter2 = "#{"AND tt.id = #{topic_id.to_i}" if topic_id}"
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sql = <<SQL
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WITH cte as (
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SELECT
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t.id,
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p.user_id,
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MAX(p.created_at) last_post_date,
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ROW_NUMBER() OVER(PARTITION BY t.id ORDER BY COUNT(*) DESC, MAX(p.created_at) DESC) as rank
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FROM topics t
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JOIN posts p ON p.topic_id = t.id
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WHERE p.deleted_at IS NULL AND
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NOT p.hidden AND
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p.post_type in (#{Topic.visible_post_types.join(",")}) AND
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p.user_id <> t.user_id AND
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p.user_id <> t.last_post_user_id
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#{filter}
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GROUP BY t.id, p.user_id
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),
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cte2 as (
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SELECT id, user_id, ROW_NUMBER() OVER(PARTITION BY id ORDER BY last_post_date ASC) as rank
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FROM cte
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WHERE rank <= #{count}
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)
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UPDATE topics tt
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SET
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featured_user1_id = x.featured_user1,
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featured_user2_id = x.featured_user2,
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featured_user3_id = x.featured_user3,
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featured_user4_id = x.featured_user4
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FROM topics AS tt2
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LEFT OUTER JOIN (
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SELECT
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c.id,
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MAX(case when c.rank = 1 then c.user_id end) featured_user1,
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MAX(case when c.rank = 2 then c.user_id end) featured_user2,
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MAX(case when c.rank = 3 then c.user_id end) featured_user3,
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MAX(case when c.rank = 4 then c.user_id end) featured_user4
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FROM cte2 as c
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GROUP BY c.id
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) x ON x.id = tt2.id
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WHERE tt.id = tt2.id AND
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(
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COALESCE(tt.featured_user1_id,-99) <> COALESCE(x.featured_user1,-99) OR
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COALESCE(tt.featured_user2_id,-99) <> COALESCE(x.featured_user2,-99) OR
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COALESCE(tt.featured_user3_id,-99) <> COALESCE(x.featured_user3,-99) OR
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COALESCE(tt.featured_user4_id,-99) <> COALESCE(x.featured_user4,-99)
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)
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#{filter2}
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SQL
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DB.exec(sql)
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end
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private
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def update_participant_count
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count = topic.posts.where('NOT hidden AND post_type in (?)', Topic.visible_post_types).count('distinct user_id')
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topic.update_columns(participant_count: count)
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end
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end
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