oracle中怎么按每小時分組。數(shù)據(jù)如下？select time，count(time) from (select substr("2014-01-01 20:03:00"，1，13) as time

oracle中怎么按每小時分組。數(shù)據(jù)如下？

select time，count(time) from (select substr("2014-01-01 20:03:00"，1，13) as time from table_name) group by time

Oracle數(shù)據(jù)庫按時間進(jìn)行分組統(tǒng)計數(shù)據(jù)的方法？

SELECT TO_CHAR(TO_DATE(20160316，"YYYYMMDD")，"W") FROM DUAL TO_CHAR函數(shù)可以獲取某一天是在該月中的第幾周，然后可以按照這個函數(shù)來分組了

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）。