SQL分組統(tǒng)計并排序？with tmp as(select row_number() over(order by count(val)) as rn，val，count(val) as cnum fr

SQL分組統(tǒng)計并排序？

with tmp as

(select row_number() over(order by count(val)) as rn，val，count(val) as cnum from table1 group by val)

select * from tmp where rn

要想?yún)^(qū)別并列現(xiàn)象還要復(fù)雜一些，可能簡單的語句解決不了

sql同一個字段先分組再排序？

應(yīng)該是先篩選比較好，會減少分組的運(yùn)算量。 sql 默認(rèn)的優(yōu)先級是 from>where>group by>select>order by where在group by 前執(zhí)行，會減少group by 的運(yùn)算量。

oracleSQL用select過程進(jìn)行分組排序查詢？

實現(xiàn)思路：通過select進(jìn)行查詢，通過group by進(jìn)行分組后，之后通過order by進(jìn)行排序。sql：select username from tablename order by username desc group by username以上就是通過username字段降序排序（升序是ASC、降序是DESC）。