MySQL - Column to Row - mysql

Question

In the original problem, we have a table that stores the date and win/loss information for each game played by a team.
the matches table
We can use the following SQL statements to get information about the number of games won and lost for each day.
SELECT match_date AS match_date,
SUM(IF(result = 'win',1,0)) AS win,
SUM(IF(result = 'lose',1,0)) AS lose
FROM matches
GROUP BY date;
We store the query results in the matches_2 table.the matches_2 table
My question is, how can we get the matches table based on the matches_2 table with a query?
In the simpler case, we can achieve the task of 'column to row' using union/union all. But that doesn't seem to work in this problem.
All relevant sql code can be found in the following fiddle：
https://dbfiddle.uk/rM-4Y_YN

Answer 1

You can use recursive CTE for this:
WITH RECURSIVE wins (mdate, w) AS
(
SELECT match_date as mdate, 1
FROM matches
WHERE win>0
UNION ALL
SELECT match_date, w + 1 FROM matches
JOIN wins on match_date=mdate
WHERE w < win
),
losses (mdate, l) AS
(
SELECT match_date as mdate, 1
FROM matches
WHERE lose>0
UNION ALL
SELECT match_date, l + 1 FROM matches
JOIN losses on match_date=mdate
WHERE l < lose
)
SELECT mdate as match_date, 'lose' FROM losses
UNION ALL
SELECT mdate as match_date, 'win' FROM wins
See a db-fiddle