This Leetcode problem Reported Posts LeetCode Solution is done in SQL.

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Reported Posts LeetCode Solution

Problem Statement

There is no primary key for this table, it may have duplicate rows.
The action column is an ENUM type of (‘view’, ‘like’, ‘reaction’, ‘comment’,’report’, ‘share’).
The extra column has optional information about the action such as a reason for report or a type of reaction.

Write an SQL query that reports the number of posts reported yesterday for each report reason. Assume today is 2019-07-05.

The result format is in the following example.

Example 1:
Input:

Output:

Explanation:
Note that we only care about report reasons with non zero number of reports.

Reported Posts LeetCode Solution MySQL

select 
  extra as report_reason, 
  count(*) as report_count 
from 
  (
    select 
      post_id, 
      extra 
    from 
      Actions 
    where 
      action_date = '2019-07-04' 
      and action = 'report' 
    group by 
      post_id, 
      extra
  ) as t 
group by 
  t.extra;Code language: SQL (Structured Query Language) (sql)

Reported Posts LeetCode Solution MySQL (Another approach)

select 
  extra as report_reason, 
  count(distinct post_id) as report_count 
from 
  Actions 
where 
  action_date = '2019-07-04' 
  and action = 'report' 
group by 
  extra;Code language: SQL (Structured Query Language) (sql)