table is roughly as follows:
id sample
1 a
2 b
3 a
4 c
5 d
6 c
Select the count of the sample grouping of id=3,4 (specified field)
select count(sample) from table where id=3 or id=4 group by sample
the current problem is that if you want to query too many id values, the query statement will be very long, and if the table is large, the rate will be very slow. I would like to ask if there is a better operation. Thank you
. BETWEEN , such as
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