每次用户搜索记录到桌面的内容时。
也会记录子搜索。它们用星号记录。
我正在尝试为每次搜索拉出最长的字符串。
用户可以进行多次搜索。
例如，User1搜索＆＃34;数据管理＆＃34;和＆＃34;状态信息＆＃34;。我想忽略记录的部分搜索（子搜索），例如＆＃34;数据管理*＆＃34;，＆＃34;数据管理*＆＃34;，＆＃34;状态在*＆＃34;并完成已完成的搜索。
表
id user data
---------------
1 user1 data manag*
2 user1 confer*
3 user1 incomplete sear*
4 user1 data managem*
5 user1 conference c*
6 user1 data management
7 user1 conference call*
8 user1 status in*
9 user1 status information
输出应为
user1 data management
user1 conference call*
user1 incomplete sear*
user1 status information
你能帮帮忙吗？
答案 0 :(得分：1)
主要想法是按p列排序数据，并将每个值与下一个值进行比较。如果下一个值不以current开头，那么当前值就是所需的结果。
简化，中间查询：
data如您所见，所需的值位于with
t(x) as (values
('data manag*'),('confer*'),('incomplete sear*'),
('data managem*'),('conference c*'),('data management'),
('conference call*'),('status in*'),('status information'))
select
*,
case
when right(x,1) != '*' then 1
when replace(x,'*','') = substring(y,1,length(replace(x,'*',''))) then 0
else 1
end hit
from
(
select
x, lead(x) over (order by x) as y /*lag(x,-1) can be used instead of lead(x)*/
from t) r;
x | y | hit
--------------------+--------------------+------
confer* | conference c* | 0
conference c* | conference call* | 0
conference call* | data manag* | 1
data manag* | data managem* | 0
data managem* | data management | 0
data management | incomplete sear* | 1
incomplete sear* | status in* | 1
status in* | status information | 0
status information | | 1
(9 rows)
列x。将其用作子查询或视图以获得最终结果。
答案 1 :(得分：1)
这样做很好：
with
searches (id, "user", data) as ( values
(1, 'user1', 'data manag*'),
(2, 'user1', 'confer*'),
(3, 'user1', 'incomplete sear*'),
(4, 'user1', 'data managem*'),
(5, 'user1', 'conference c*'),
(6, 'user1', 'data management'),
(7, 'user1', 'conference call*'),
(8, 'user1', 'status in*'),
(9, 'user1', 'status information')
)
select "user", data
from searches s
where data not like '%*'
or not exists (
select 1
from searches
where "user" = s."user"
and id <> s.id
and data like (left(s.data, -1)||'%')
)
答案 2 :(得分：0)
SELECT user, data
FROM (
SELECT user,
data,
ROW_NUMBER() over ( PARTITION BY user
ORDER BY char_length(data) DESC) rn
FROM table
) t
WHERE t.rn = 1