SQL> select ID,rank() over(order by ID) RANK , dense_rank() over(order by ID) DENSE_RANK from a;
ID RANK DENSE_RANK
1 1 1
1 1 1
2 3 2
3 4 3
3 4 3
4 6 4
5 7 5
5 7 5
6 9 6
7 10 7
Related
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0
I expect I'm just missing something, but if I run this query without the "connect by", I get 2 rows. When I add "connect by level <= 4", I would expect to get each of those 2 rows 4 times. The actual result is different.
Can anyone help me understand what's happening here? I'm not looking for a solution that only repeats each row 4 times - I've already got that. I'm just looking to understand what's happening and why.
with alpha as (
select 1 as id
from dual
),
beta as (
select 1 as alpha_id,
1 as beta_no
from dual
union all
select 1 as alpha_id,
2 as beta_no
from dual
)
select a.id,
b.beta_no,
level as the_level
from alpha a
inner join beta b
on b.alpha_id = a.id
connect by level <= 4
order by a.id,
b.beta_no,
level
;
ID BETA_NO THE_LEVEL
1 1 1
1 1 2
1 1 2
1 1 3
1 1 3
1 1 3
1 1 3
1 1 4
1 1 4
1 1 4
1 1 4
1 1 4
1 1 4
1 1 4
1 1 4
1 2 1
1 2 2
1 2 2
1 2 3
1 2 3
1 2 3
1 2 3
1 2 4
1 2 4
1 2 4
1 2 4
1 2 4
1 2 4
1 2 4
1 2 4
30 rows selected
Many thanks to mathguy. The second link he provided in the answer below had exactly what I was looking for. Specifically:
1 with t as (select 1 as id from dual union all
2 select 2 from dual)
3 --
4 select id, level
5 ,prior id
6 ,sys_connect_by_path(id,'=>') as cpath
7 from t
8* connect by level <= 3
SQL> /
ID LEVEL PRIORID CPATH
---------- ---------- ---------- --------------------------------------------------
1 1 =>1
1 2 1 =>1=>1
1 3 1 =>1=>1=>1
2 3 1 =>1=>1=>2
2 2 1 =>1=>2
1 3 2 =>1=>2=>1
2 3 2 =>1=>2=>2
2 1 =>2
1 2 2 =>2=>1
1 3 1 =>2=>1=>1
2 3 1 =>2=>1=>2
2 2 2 =>2=>2
1 3 2 =>2=>2=>1
2 3 2 =>2=>2=>2
14 rows selected.
It's clear to me from that example, but I'd be hard-pressed to succinctly put it into words.
With no condition other than "level <= 4", every row from the original table, view etc. (from the join, in this case) will produce two rows at level 2, then four more rows at level 3, and 8 more at level 4. "Connect by" is essentially a succession of joins, and you are doing cross joins if you have no condition with the PRIOR operator.
You probably want to add "and prior a.id = a.id". This will lead to Oracle complaining about cycles (because Oracle decides a cycle is reached when it sees the same values in the columns subject to PRIOR). That, in turn, is solved by adding a third condition, usually "and prior sys_guid() is not null".
(Edited; the original answer made reference to NOCYCLE, which is not needed when using the "prior sys_guid() is not null" approach.)
This has been discussed recently on OTN: https://community.oracle.com/thread/3999985
Same question discussed here: https://community.oracle.com/thread/2526535
To illustrate Mathguy's answer, you are missing some predicates out of your CONNECT BY clause:
with alpha as (
select 1 as id
from dual
),
beta as (
select 1 as alpha_id,
1 as beta_no
from dual
union all
select 1 as alpha_id,
2 as beta_no
from dual
)
select a.id,
b.beta_no,
level as the_level
from alpha a
inner join beta b
on b.alpha_id = a.id
connect by level <= 4
AND PRIOR a.id = a.id
AND PRIOR b.beta_no = b.beta_no
AND PRIOR sys_guid() IS NOT NULL
order by a.id,
b.beta_no,
LEVEL;
ID BETA_NO THE_LEVEL
---------- ---------- ----------
1 1 1
1 1 2
1 1 3
1 1 4
1 2 1
1 2 2
1 2 3
1 2 4
An alternative would be to use the recursive with clause:
with alpha as (
select 1 as id
from dual
),
beta as (
select 1 as alpha_id,
1 as beta_no
from dual
union all
select 1 as alpha_id,
2 as beta_no
from dual
),
multiply (id, beta_no, rn) AS (SELECT a.id,
b.beta_no,
1 rn
FROM alpha a
INNER JOIN beta b
ON a.id = b.alpha_id
UNION ALL
SELECT ID,
beta_no,
rn + 1
FROM multiply
WHERE rn + 1 <= 4)
SELECT ID,
beta_no,
rn AS the_level
FROM multiply
order by id,
beta_no,
rn;
ID BETA_NO THE_LEVEL
---------- ---------- ----------
1 1 1
1 1 2
1 1 3
1 1 4
1 2 1
1 2 2
1 2 3
1 2 4
i have a table in hive with two columns: session_id and duration_time like this:
|| session_id || duration||
1 14
1 10
1 20
1 10
1 12
1 16
1 8
2 9
2 6
2 30
2 22
i want to add a new column with unique id when:
the session_id is changing or the duration_time > 15
i want the output to be like this:
session_id duration unique_id
1 14 1
1 10 1
1 20 2
1 10 2
1 12 2
1 16 3
1 8 3
2 9 4
2 6 4
2 30 5
2 22 6
any ideas how to do that in hive QL?
thanks!
SQL tables represent unordered sets. You need a column specifying the ordering of the values, because you seem to care about the ordering. This could be an id column or a created-at column, for instance.
You can do this using a cumulative sum:
select t.*,
sum(case when duration > 15 or seqnum = 1 then 1 else 0 end) over
(order by ??) as unique_id
from (select t.*,
row_number() over (partition by session_id order by ??) as seqnum
from t
) t;
ORACLE select
calculate Sales، returns and the rest for a customer in the same table for the same product according to trans type
i need to calculate total sales and total returns and the rest for the customer and items.
and group by customer
Trans_Type:
1= Sales
2= Return
ID Trans_Type DATE Items_ID Quantity Clint_ID
--- ---------- -------- ---------- ---------- ----------
1 1 16-OCT-09 701555 3 1
2 2 12-DEC-09 701555 1 1
3 1 30-JUL-10 701511 63 2
4 2 30-JUL-10 701555 1 1
5 1 30-JUL-10 701234 2 3
6 1 30-JUL-10 701234 5 3
7 2 30-JUL-10 701511 1 2
8 1 30-JUL-10 701522 3 2
9 1 30-JUL-10 701555 2 3
10 1 30-JUL-10 701555 4 2
11 2 30-JUL-10 701555 2 2
If I understood everything correct you need to use case when ... and group by ... clauses, like here:
select clint_id, items_id, qty, ret, nvl(qty,0) - nvl(ret,0) rest
from (
select clint_id, items_id,
sum(case when trans_type = 1 then quantity end) qty,
sum(case when trans_type = 2 then quantity end) ret
from data group by clint_id, items_id )
order by clint_id, items_id
SQLFiddle demo
I have problem with LINQ Query in following scenario:
I have Activity and ActivityTeacher Two Table and List of Some Teachers.
Activity Table
ActivityID Date Class
1 4/4/2012 1
2 4/5/2013 2
3 4/6/2013 5
4 5/6/2013 2
5 5/16/2013 1
6 5/20/2013 8
7 5/21/2013 7
8 6/22/2013 6
9 8/10/2013 5
10 8/12/2013 4
ActivityTeacher Table
ActivityID TeacherID
1 2
1 3
1 4
2 6
3 6
3 6
3 4
2 5
4 2
4 3
4 6
5 8
5 7
5 6
6 6
6 7
6 9
6 10
6 1
6 2
7 2
7 8
7 9
7 10
8 3
8 4
8 6
8 7
9 10
9 3
9 2
10 1
10 2
List of Teachers={2,3,4}
Now I want to select records from Activity based on List of Teachers={2,3,4}
without using foreach loop.
The Activity entity should have a Teachers navigation property you can utilize:
context.Activities
.Where(x => listOfTeachers.Contains(x.Teachers.Select(t => t.TeacherId)));
If listOfTeachers contains the three IDs 2, 3, 4, this query should translate to SQL that is similar to the following:
select a.*
from Activity a
inner join ActivityTeacher at
on a.activityid = at.activityid
where at.teacherid in (2, 3, 4);
I need an o/p as below.
1,1
2,1
2,2
3,1
3,2
3,3
4,1
4,2
4,3
4,4
... and so on.
I tried to write the query as below. But throwing error. SIngle row subquery returns more than one row.
with test1 as(
SELECT LEVEL n
FROM DUAL
CONNECT BY LEVEL <59)
select n,(
SELECT LEVEL n
FROM DUAL
CONNECT BY LEVEL <n) from test1
Appreciate your help in solving the same.
Here is one of the methods how you could get the desired result:
SQL> with t1(col) as(
2 select level
3 from dual
4 connect by level <= 5
5 )
6 select a.col
7 , b.col
8 from t1 a
9 join t1 b
10 on a.col >= b.col
11 ;
COL COL
---------- ----------
1 1
2 1
2 2
3 1
3 2
3 3
4 1
4 2
4 3
4 4
5 1
5 2
5 3
5 4
5 5
15 rows selected