Adding a row number respecting the order of each row - sql

I have a table like this
id, period, tag
1 1 A
1 2 A
1 3 B
1 4 A
1 5 A
1 6 A
2 1 A
2 2 B
2 3 B
2 4 B
2 5 B
2 6 A
I would like to add a new column with a ranking, respecting the order of the row given my column 'period' to obtain something like this
id, period, tag rank
1 1 A 1
1 2 A 1
1 3 B 2
1 4 A 3
1 5 A 3
1 6 A 3
2 1 A 1
2 2 B 2
2 3 B 2
2 4 B 2
2 5 B 2
2 6 A 3
What can I do?
I try rank and dense_rank function without any success

And another candidate for CONDITIONAL_CHANGE_EVENT()
less code, and quite effective, too ...!
WITH
input(id,period,tag) AS (
SELECT 1,1,'A'
UNION ALL SELECT 1,2,'A'
UNION ALL SELECT 1,3,'B'
UNION ALL SELECT 1,4,'A'
UNION ALL SELECT 1,5,'A'
UNION ALL SELECT 1,6,'A'
UNION ALL SELECT 2,1,'A'
UNION ALL SELECT 2,2,'B'
UNION ALL SELECT 2,3,'B'
UNION ALL SELECT 2,4,'B'
UNION ALL SELECT 2,5,'B'
UNION ALL SELECT 2,6,'A'
)
SELECT
*
, CONDITIONAL_CHANGE_EVENT(tag) OVER(PARTITION BY id ORDER BY period) + 1 AS rank
FROM input;
-- out id | period | tag | rank
-- out ----+--------+-----+------
-- out 1 | 1 | A | 1
-- out 1 | 2 | A | 1
-- out 1 | 3 | B | 2
-- out 1 | 4 | A | 3
-- out 1 | 5 | A | 3
-- out 1 | 6 | A | 3
-- out 2 | 1 | A | 1
-- out 2 | 2 | B | 2
-- out 2 | 3 | B | 2
-- out 2 | 4 | B | 2
-- out 2 | 5 | B | 2
-- out 2 | 6 | A | 3
-- out (12 rows)
-- out
-- out Time: First fetch (12 rows): 14.823 ms. All rows formatted: 14.874 ms

One method is a cumulative sum based on a lag():
select t.*,
sum(case when prev_tag = tag then 0 else 1 end) over (partition by id order by period) as rank
from (select t.*, lag(tag) over (partition by id order by period) as prev_tag
from t
) t;

Related

Vertica - Union with Group by is possible?

I have two tables like this :
Nu
i j
1 2
1 3
1 4
Nv
i j
2 1
2 5
3 1
3 6
What I want to do is I need to find :
Select j From Nu UNION Select j from Nv) for every Distinct (Nu.i , Nv.i)
Like this :
Nu.i Nv.i v
1 2 2
1 2 3
1 2 4
1 2 1
1 2 5
1 3 2
1 3 3
1 3 4
1 3 1
1 3 6
Is there any way I can query this with Vertica SQL?
I tried :
Select
Nu.i,
Nv.i,
(Select j from Nu UNION Select j from Nv group by Nv.j) as v
from Nu, Nv;
Error :
ERROR 4840: Subquery used as an expression returned more than one row
And :
Select
Nu.i,
Nv.i,
(Select j from Nu UNION Select j from Nv) as v
from Nu, Nv
group by Nu.i, Nv.i;
Error:
Subqueries in the SELECT or ORDER BY are not supported if the subquery
is not part of the GROUP BY
Please, let me know you suggestion.
Your result table is somehow unexpected to me - I can't figure out the rules on how you would want it to be generated.
Nu has 3 rows. Nv has 4 rows. I was thinking of a CROSS JOIN between the two tables, but that would lead to 3 x 4, that's 12 rows. Like so:
WITH
Nu (i,j) AS (
SELECT 1,2
UNION ALL SELECT 1,3
UNION ALL SELECT 1,4
)
,
Nv(i,j) AS (
SELECT 2,1
UNION ALL SELECT 2,5
UNION ALL SELECT 3,1
UNION ALL SELECT 3,6
)
SELECT
Nu.i AS "Nu.i"
, Nv.i AS "Nv.i"
, Nu.j AS "Nu.j"
, Nv.j AS "Nv.j"
FROM Nu CROSS JOIN Nv;
-- out Nu.i | Nv.i | Nu.j | Nv.j
-- out ------+------+------+------
-- out 1 | 2 | 2 | 1
-- out 1 | 2 | 3 | 1
-- out 1 | 2 | 4 | 1
-- out 1 | 2 | 2 | 5
-- out 1 | 2 | 3 | 5
-- out 1 | 2 | 4 | 5
-- out 1 | 3 | 2 | 1
-- out 1 | 3 | 3 | 1
-- out 1 | 3 | 4 | 1
-- out 1 | 3 | 2 | 6
-- out 1 | 3 | 3 | 6
-- out 1 | 3 | 4 | 6
-- out (12 rows)
-- out
-- out Time: First fetch (12 rows): 14.037 ms. All rows formatted: 14.086 ms
But could it be that, seeing this result table, you can figure out the rest by yourself?

query to count occurances of aparticular column value

Let's say I have a table with the following value
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
I need to get an out put like this, which counts each occurances of a
particular value
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3
1 1
1 2
1 3
2 1
2 2
2 3
NB: This is a sample table Actual table is a complex table with lots of rows and columns and query contains some more conditions
If the number repeats over different "islands" then you need to calculate a value to maintain those islands first (grpnum). That first step can be undertaken by subtracting a raw top-to-bottom row number (raw_rownum) from a partitioned row number. That result gives each "island" a reference unique to that island that can then be used to partition a subsequent row number. As each order by can disturb the outcome I find it necessary to use individual steps and to pass the prior calculation up so it may be reused.
SQL Fiddle
MS SQL Server 2014 Schema Setup:
CREATE TABLE Table1 ([num] int);
INSERT INTO Table1 ([num])
VALUES (1),(1),(1),(2),(2),(2),(3),(3),(3),(1),(1),(1),(2),(2),(2);
Query 1:
select
num
, row_number() over(partition by (grpnum + num) order by raw_rownum) rn
, grpnum + num island_num
from (
select
num
, raw_rownum - row_number() over(partition by num order by raw_rownum) grpnum
, raw_rownum
from (
select
num
, row_number() over(order by (select null)) as raw_rownum
from table1
) r
) d
;
Results:
| num | rn | island_num |
|-----|----|------------|
| 1 | 1 | 1 |
| 1 | 2 | 1 |
| 1 | 3 | 1 |
| 2 | 1 | 5 |
| 2 | 2 | 5 |
| 2 | 3 | 5 |
| 1 | 1 | 7 |
| 1 | 2 | 7 |
| 1 | 3 | 7 |
| 3 | 1 | 9 |
| 3 | 2 | 9 |
| 3 | 3 | 9 |
| 2 | 1 | 11 |
| 2 | 2 | 11 |
| 2 | 3 | 11 |
SQL Server provide row_number() function :
select ID, ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ID) RN FROM <TABLE_NAME>
EDIT :
select * , case when (row_number() over (order by (select 1))) %3 = 0 then 3 else
(row_number() over (order by (select 1))) %3 end [rn] from table
I think there is a problem with your sample, in that you have an implied order but not an explicit one. There is no guarantee that the database will keep and store the values the way you have them listed, so there has to be some inherent/explicit ordering mechanism to tell the database to give those values back exactly the way you listed.
For example, if you did this:
update test
set val = val + 2
where val < 3
You would find your select * no longer comes back the way you expected.
You indicated your actual table was huge, so I assume you have something like this you can use. There should be something in the table to indicate the order you want... a timestamp, perhaps, or maybe a surrogate key.
That said, assuming you have something like that and can leverage it, I believe a series of windowing functions would work.
with rowed as (
select
val,
case
when lag (val, 1, -1) over (order by 1) = val then 0
else 1
end as idx,
row_number() over (order by 1) as rn -- fix this once you have your order
from
test
),
partitioned as (
select
val, rn,
sum (idx) over (order by rn) as instance
from rowed
)
select
val, instance, count (1) over (partition by instance order by rn)
from
partitioned
This example orders by the way they are listed in the database, but you would want to change the row_number function to accommodate whatever your real ordering mechanism is.
1 1 1
1 1 2
1 1 3
2 2 1
2 2 2
2 2 3
3 3 1
3 3 2
3 3 3
1 4 1
1 4 2
1 4 3
2 5 1
2 5 2
2 5 3

Oracle query for selecting sampling of number values from a table

I have a data field in my Oracle DB Table whose datatype is NUMBER. I have tried a query below using order by.
SELECT Value
FROM Table
ORDER BY value;
I am getting the result as
Value |
------|
1 |
1 |
2 |
2 |
3 |
3 |
4 |
4 |
5 |
5 |
6 |
6 |
Instead I want a result as
Value |
------|
1 |
2 |
3 |
4 |
5 |
6 |
1 |
2 |
3 |
4 |
5 |
6 |
You can use the row_number to evaluate if an occurrence of a value is the first one, the second, and so on; an order by based on this value and then for the value in the table will do the work.
For example:
/* a test case */
with someTable(value) as (
select 1 from dual union all
select 2 from dual union all
select 3 from dual union all
select 4 from dual union all
select 5 from dual union all
select 6 from dual union all
select 1 from dual union all
select 2 from dual union all
select 3 from dual union all
select 4 from dual union all
select 5 from dual union all
select 6 from dual
)
/* the query */
select value
from someTable
order by row_number() over ( partition by value order by null), value
How it works:
select value, row_number() over ( partition by value order by null) rowNumber
from someTable
order by row_number() over ( partition by value order by null), value
gives:
VALUE ROWNUMBER
---------- ----------
1 1
2 1
3 1
4 1
5 1
6 1
1 2
2 2
3 2
4 2
5 2
6 2
Please try this. I'm using ROW_NUMBER() to arrange the values based on their occurrences,
SELECT VALUE
FROM (
SELECT VALUE
, ROW_NUMBER() OVER (PARTITION BY VALUE ORDER BY VALUE ASC) RNK
FROM MY_TABLE
)
ORDER BY RNK
, VALUE;
1 Value | ------| 1 | 1 | 2 | 2 | 3 | 3 | 4 | 4 | 5 | 5 | 6 | 6 |
SELECT ROW_NUMBER() OVER (PARTITION BY VALUE ORDER BY VALUE) AS RN, TABLE .* FROM TABLE
2 Value | ------| 1 | 2 | 3 | 4 | 5 | 6 | 1 | 2 | 3 | 4 | 5 | 6 |
SELECT ROWNUM,TABLE.* FROM TABLE

Select non distinct rows from two columns

My question is very similar to Multiple NOT distinct only it deals with multiple columns instead of one. I have a table like so:
A B C
1 1 0
1 2 1
2 1 2
2 1 3
2 2 4
2 3 5
2 3 6
3 1 7
3 3 8
3 1 9
And the result should be:
A B C
2 1 2
2 1 3
2 3 5
2 3 6
3 1 7
3 1 9
Essentially, like the above question, removing all unique entries only where uniqueness is determined by two columns instead of one. I already tried various tweaks to the above answer but couldn't get any of them to work.
You are using SQL Server, so this is easier than in Access:
select A, B, C
from (select t.*, count(*) over (partition by A, B) as cnt
from t
) t
where cnt > 1;
This use of count(*) is as a window function. It is counting the number of rows with the same value of A and B. The final where just selects the rows that have more than one entry.
Another possible solution with EXISTS
SELECT a, b, c
FROM Table1 t
WHERE EXISTS
(
SELECT 1
FROM Table1
WHERE a = t.a
AND b = t.b
AND c <> t.c
)
It should be fast enough.
Output:
| A | B | C |
-------------
| 2 | 1 | 2 |
| 2 | 1 | 3 |
| 2 | 3 | 5 |
| 2 | 3 | 6 |
| 3 | 1 | 7 |
| 3 | 1 | 9 |
Here is SQLFiddle demo

SQL Select records excluding some statuses

I'm totally stuck on how to create this select. I need to select from the status table only those order_id's which to not have status 2.
Here is the table:
+----+---------+---------+--
| id | order_id| status |
+----+---------+---------+--
| 1 | 1 | 1 |
| 2 | 1 | 2 |
| 3 | 2 | 1 |
| 4 | 2 | 2 |
| 5 | 3 | 1 |
| 1 | 3 | 3 |
| 2 | 4 | 2 |
| 3 | 4 | 1 |
| 4 | 4 | 2 |
| 5 | 5 | 3 |
+----+---------+----------+--
So he select result will be only order_id = 5
Please help!
If you want to include orders with status 1 and exclude those with status 3, then you can use a similar idea:
having sum(case when status_id = 1 then 1 else 0 end) > 0 and
sum(case when status_id = 3 then 1 else 0 end) = 0
EDIT: I like to EXCLUDE those order_id's:
- Which has only status 1 (not status 2)
- and
- which has status 3
Lets have table like this:
id--order-id-Prod---Status
------------------------------
1 1 a 1
6 1 b 2
7 1 a 2
8 1 b 1
9 2 a 1
10 3 a 1
11 3 b 1
12 3 a 2
13 3 b 2
14 4 a 1
15 4 b 1
16 5 a 1
17 5 b 1
18 5 a 2
19 5 b 2
20 5 a 3
21 5 b 3
Select should show only order_id "5"
This is an example of a set-within-sets query:
select order_id
from t
group by order_id
having sum(case when status = 2 then 1 else 0 end) = 0
The having clause counts the number of rows with a status of 2. The = 0 finds the orders with no matches.
EDIT:
If you want to include orders with status 1 and exclude those with status 3, then you can use a similar idea:
having sum(case when status_id = 1 then 1 else 0 end) > 0 and
sum(case when status_id = 3 then 1 else 0 end) = 0
Here's one way.
Select * from TableName
where Order_ID not in (Select order_ID from tableName where status=2)
Another way would be to use the not exists clause.
Another way is to use EXCEPT:
SELECT order_id
FROM StatusTable
EXCEPT
SELECT order_id
FROM StatusTable
WHERE status = 2;
It works in SQL-Server and Postgres (and in Oracle if you replace the EXCEPT with MINUS.)
I think this works, one query to select all ids, one to get those with a status of 2 and left joining on order_id and picking those with null order_id in the list of orders with a status of 2.
select
all_ids.order_id
from
(
select distinct
order_id
from status
) all_ids
left join
(
select
order_id
from status
where status = 2
) two_ids
on all_ids.order_id = two_ids.order_id
where two_ids.order_id is null