Cannot return the record that match the condition

I have a table which contains a list of match:

id        |  datetime 
 2864049     2019-04-03 00:00:00
 2864050     2019-04-03 00:00:00
 2864051     2019-04-03 00:00:00

Essentially, I have to check if it exists and if it needs to be updated, for doing so I did:

SELECT mm.match_id
FROM (SELECT 2864049 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime UNION ALL 
      SELECT 2864050 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime UNION ALL 
      SELECT 2864051 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime
     ) mm LEFT JOIN
     `match` m
     on m.id = mm.match_id AND m.datetime <> mm.match_datetime
WHERE m.id IS NULL

The problem is that this query shouldn’t return any result, because all the three match exists, and also have the datetime field equal to the matches provided in the mm table.

The query need to return a result only if the datetime is different or if the match doesn’t exist.

What I did wrong?

Answer

Move the different date to where clause

Live test: http://sqlfiddle.com/#!9/ee7ffb/1

CREATE TABLE `match`
    (`id` int, `datetime` datetime)
;

INSERT INTO `match`
    (`id`, `datetime`)
VALUES
    (2864049, '2019-04-03 00:00:00'),
    (2864050, '2019-04-03 00:00:00'),
    (2864051, '2019-04-03 00:00:00'),
    (2864052, '2019-04-03 00:00:00'),
    (2864053, '2019-04-03 00:00:00'),    
    (2864054, '2019-04-03 00:00:00')        
;



SELECT m.id, `datetime`
FROM 
`match` `m`
left join  
     (SELECT 2864049 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime UNION ALL 
      SELECT 2864050 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime UNION ALL 
      SELECT 2864051 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime union all
      SELECT 2864052 as match_id, CAST("2019-04-04 00:00:00" AS DATETIME) AS match_datetime union all
      SELECT 2864054 as match_id, CAST("2019-04-03 00:00:00" AS DATETIME) AS match_datetime  
     ) mm 
     on m.id = mm.match_id 
WHERE 
mm.match_id IS NULL -- not existing
or m.datetime <> mm.match_datetime -- move to where clause

Output:

|      id |             datetime |
|---------|----------------------|
| 2864052 | 2019-04-03T00:00:00Z |
| 2864053 | 2019-04-03T00:00:00Z |

2864052 appears despite it has a matching id as its datetime is different from mm’s

2864053 appears as it is not existing on mm