具有最高 COUNT 的 MySQL GROUP BY 字段(基于 JOIN)

Question

SELECT COUNT(dev_link.id) c, pattern.direction, pattern.section, (
    SELECT to_stop AS `stop`
    FROM dev_link d
    WHERE d.section = section
    ORDER BY d.sequence DESC
    LIMIT 1
) code
FROM pattern
INNER JOIN dev_link ON dev_link.section = pattern.section
WHERE pattern.service = "YSEO252"
GROUP BY pattern.code
ORDER BY c DESC

上面是一个查询及其结果。目前这选择了太多数据，我需要将其缩小到以下范围:

1 行方向为outbound，另一行方向为inbound。如果只是我可以轻松地 GROUP BY 方向。但是，我需要选择具有最高 c 值的 inbound 和 outbound 行。所以根据上面的结果，第一行和第三行将被选中。

如何更改我的查询以使其返回这些行？

Answer 1

( SELECT ... WHERE ... AND pattern.direction='inbound' ... LIMIT 1)
UNION ALL
( SELECT ... WHERE ... AND pattern.direction='outbound' ... LIMIT 1 );

否则，每个 SELECT 都像原来的一样。