Question

I am dealing with an issue and need some expert advice on to achieve the problem, my sql query generates output with two columns, 1st column displays id (for e.g. abc-123 in following table) and next column displays corresponding result to the id stored in db which is pass or fail.

I need to implement, when resolution is pass it should display success attempt, in following example, abc-123 failed 1st time however def-456 passed in next attempt thus success rate is 50%, now counter should reset and go to next row where there is pass thus it should show 100%, again when code hits pass counter resets then goes next and displays 33% bec there are two fail and one pass at the end, how it can be achieved in sql? (id and resolution are column names)

**date**       **id resolution**    
 6/6/2012     abc-123   fail       50%
 6/7/2012     abc-456   pass    
 6/8/2012     abc-789   pass       100%
 6/9/2012     abc-799   fail       33%
 6/10/2012    abc-800   fail    
 6/1/2012     abc-900   pass

Thanks

Answer 1

SELECT
  *
FROM
  table
INNER JOIN
(
  SELECT
    MIN(g.id)   AS first_id,
    MAX(g.id)   AS last_id,
    COUNT(*)    AS group_size
  FROM
    table AS p
  INNER JOIN
    table AS g
      ON g.id > COALESCE(
                  (SELECT MAX(id) FROM table WHERE id < p.id AND resolution = 'pass'),
                  ''
                )
     AND g.id <= p.id
  WHERE
    p.resolution = 'pass'
  GROUP BY
    p.id
)
  AS groups
    ON  table.id >= groups.first_id
    AND table.id <= groups.last_id