Oracle lag()/lead() over()分析函数

Oracle lag()/lead() over()分析函数

with tmp as(
select '1' id ,'aa' name ,'22' age from dual union all
select '2' id ,'bb' name ,'20' age from dual union all
select '3' id ,'CC' name ,'21' age from dual
)
select a.*,
       lead(age,1) over (order by id desc) lag,
  a.age - lead(age,1) over (order by id desc) lag1
from tmp a

lead函数是按id倒序排序把下一行的age记录显示在当前行的列lag,为null显示null

with tmp as(
select '1' id ,'aa' name ,'22' age from dual union all
select '2' id ,'bb' name ,'20' age from dual union all
select '3' id ,'CC' name ,'21' age from dual
)
select a.*,
       lag(age,1) over (order by id desc) lag,
  a.age - lag(age,1) over (order by id desc) lag1
from tmp a

lag函数是按id倒序排序把上一行的age记录显示在当前行的列lag,为null显示null