A have a column named key - 1,1,2,2,2,2,3 Now i do it with 3 querys:
SELECT count(key) as k FROM `test` WHERE key=1
SELECT count(key) as k FROM `test` WHERE key=2
SELECT count(key) as k FROM `test` WHERE key=3
How to count in one query how many 1,2,3?
使用分组:
SELECT `key`, COUNT(*) FROM `test` GROUP BY `key`;
你可以这样做
select count(key) as K FROM test where key in (1,2,3)
This is another option:
SELECT sum(key=1) as k1, sum(key=2) as k2,sum(key=3) as k3 FROM `test`
you could also add a group by column if the values of key were part of some other group.
Try this
SELECT COUNT(Key) as K
FROM
test
GROUP BY Key
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