由 dawei 我需要帮助在Oracle中编写查询以获取以下数据.数据按人员和日期字段排序.
Person Day Flag
------ --- ----
person1 day1 Y
person1 day2 Y
person1 day3 Y
person1 day4 N
person1 day5 N
person1 day6 Y
person1 day7 Y
person1 day8 Y
我需要有一个Group_Number列,只要Flag值发生变化就会增加.我的结果应如下所示
Person Day Flag Group_Number
------ --- ---- ------------
person1 day1 Y 1
person1 day2 Y 1
person1 day3 Y 1
person1 day4 N 2
person1 day5 N 2
person1 day6 Y 3
person1 day7 Y 3
person1 day8 Y 3
我认为有办法使用分析函数,如ROW_NUMBER,LEAD等获得上述结果.
您可以将
analytic functions SUM(用作运行总计)和
LAG组合在一起：
SQL> WITH data AS ( 2 SELECT 'person1' person,'day1' day,'Y' flag FROM dual 3 UNION ALL SELECT 'person1' person,'day2' day,'Y' flag FROM dual 4 UNION ALL SELECT 'person1' person,'day3' day,'Y' flag FROM dual 5 UNION ALL SELECT 'person1' person,'day4' day,'N' flag FROM dual 6 UNION ALL SELECT 'person1' person,'day5' day,'N' flag FROM dual 7 UNION ALL SELECT 'person1' person,'day6' day,'Y' flag FROM dual 8 UNION ALL SELECT 'person1' person,'day7' day,'Y' flag FROM dual 9 UNION ALL SELECT 'person1' person,'day8' day,'Y' flag FROM dual 10 ) 11 SELECT person,DAY,flag,SUM(gap) over (PARTITION BY person 12 ORDER BY DAY) grp 13 FROM (SELECT person,14 CASE WHEN flag = lag(flag) over (PARTITION BY person 15 ORDER BY DAY) 16 THEN 0 17 ELSE 1 18 END gap 19 FROM DATA); PERSON DAY FLAG GRP ------- ---- ---- ---------- person1 day1 Y 1 person1 day2 Y 1 person1 day3 Y 1 person1 day4 N 2 person1 day5 N 2 person1 day6 Y 3 person1 day7 Y 3 person1 day8 Y 3