SELECT t.*FROM (SELECT @rownum := 0) rJOIN table tWHERE (@rownum :=@rownum + 1) <= ( SELECT round(count(*) * 0.2)
-- 0.2查的就是20% FROM table ); table 就是实际的表名称
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分两条
SELECT ceil(count(1)*0.2) as t from fn_open
SELECT * from fn_open limit t
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| limit count(id)* 0.2 |
|---|