I've the following table (both A and B are integers):
Update 1 - Could anyone do me a favour and run the solution on a set of 1M records with B being a random decimal (to avoid overflows) residing in [0 to 1] range for N=> 10, 100 and 1000? I'd like to get a flavor of the time, required to run the solution query. Thanks a lot in advance.
Sample data:
A B
1 1
2 8
3 1
4 11
5 1
6 1
7 6
8 1
9 1
10 2
How do I get the maximum Sum of B values for any N sequential A's? The solution mustn't use cursors, usage of table vars/tem tables has to be stongly justified.
I can use SQLCLR in case if it'll give a distinct performance boost.
Some clarifications:
Max Sum for 1 element is 11 (see A = 4)
Max Sum for 2 elements is 12 (it's either A=> 1 & 2 or A=> 2 & 3),
Max Sum for 3 elements is 20 (A=>2, 3, 4),
Max Sum for 4 is 21 (A=>1,2,3,4 or A=>2,3,4,5) etc.
Since the A values are guaranteed to be consecutive integers, given N we know for any particular A which values we are interested in. So
SELECT
A,
(SELECT SUM(B) FROM Table T2 WHERE T.A <= T2.A AND T2.A <= T.A + N - 1)
AS SumOfBs
FROM Table T
WHERE A + N - 1 <= (SELECT COUNT(*) FROM Table)
gives, for each A, the sum of the B values for the N rows starting there. The WHERE restricts us to rows that do actually have N rows starting there. Put this in a subquery and we can get the maximum:
SELECT
MAX(SumOfBs) AS DesiredValue
FROM
(
SELECT
A,
(SELECT SUM(B) FROM Table T2 WHERE T.A <= T2.A AND T2.A <= T.A + N - 1)
AS SumOfBs
FROM Table T
WHERE A + N - 1 <= (SELECT COUNT(*) FROM Table)
) Intermediate
should do the job.
I've loaded your test data into a table called data.
The following SQL gives me the answer 20 for N=3:
declare #N int
set #N = 3
select max(SumB)
from data d
cross apply (select SumB = SUM(B) from data sub where sub.A between d.A - (#N-1) and d.A) x
Try:
with cte as
(select 1 window_count union all
select window_count+1 window_count from cte where window_count<#N)
select max(sum_B) from
(select T1.A,
sum(T2.B) sum_B
from MyTable T1
cross join cte
join MyTable T2 on T1.A = T2.A + cte.window_count - 1
group by T1.A) sq
I'm possibly not understanding the question fully, but it looks to me like...
SELECT SUM(B) FROM table WHERE A <= n
If not correct, can you explain a bit more?
Related
I already asked for help on a part of my problem here.
I used to get 10 rows no matter if there are filled or not. But now I'm facing something else where I need to do it multiple times in the same query result.
WITH NUMBERS AS
(
SELECT 1 rowNumber
UNION ALL
SELECT 2
UNION ALL
SELECT 3
UNION ALL
SELECT 4
UNION ALL
SELECT 5
UNION ALL
SELECT 6
UNION ALL
SELECT 7
UNION ALL
SELECT 8
UNION ALL
SELECT 9
UNION ALL
SELECT 10
)
SELECT DISTINCT sp.SLC_ID, c.rowNumber, c.PCE_ID
FROM SELECT_PART sp
LEFT JOIN (
SELECT b.*
FROM NUMBERS
LEFT OUTER JOIN (
SELECT a.*
FROM (
SELECT SELECT_PART.SLC_ID, ROW_NUMBER() OVER (ORDER BY SELECT_PART.SLC_ID) as
rowNumber, SELECT_PART.PCE_ID
FROM SELECT_PART
WHERE SELECT_PART.SLC_ID = (must be the same as sp.SLC_ID and can''t hardcode it)
) a
) b
ON b.rowNumber = NUMBERS.rowNumber
) c ON c.SLC_ID = sp.SLC_ID
ORDER BY sp.SLC_ID, c.rowNumber
It works fine for the first 10 lines, but next SLC_ID only got 1 empty line
I need it to be like that
SLC_ID rowNumer PCE_ID
1 1 0001
1 2 0002
1 3 NULL
1 ... ...
1 10 NULL
2 1 0011
2 2 0012
2 3 0013
2 ... ...
2 10 0020
3 1 0021
3 ... ...
Really need it that way to build a report.
Instead of manually building a query-specific number list where you have to include every possible number you need (1 through 10 in this case), create a numbers table.
DECLARE #UpperBound INT = 1000000;
;WITH cteN(Number) AS
(
SELECT ROW_NUMBER() OVER (ORDER BY s1.[object_id]) - 1
FROM sys.all_columns AS s1
CROSS JOIN sys.all_columns AS s2
)
SELECT [Number] INTO dbo.Numbers
FROM cteN WHERE [Number] <= #UpperBound;
CREATE UNIQUE CLUSTERED INDEX CIX_Number ON dbo.Numbers([Number])
WITH
(
FILLFACTOR = 100, -- in the event server default has been changed
DATA_COMPRESSION = ROW -- if Enterprise & table large enough to matter
);
Source: mssqltips
Alternatively, since you can't add data, use a table that already exists in SQL Server.
WITH NUMBERS AS
(
SELECT DISTINCT Number as rowNumber FROM master..spt_values where type = 'P'
)
SELECT DISTINCT sp.SLC_ID, c.rowNumber, c.PCE_ID
FROM SELECT_PART sp
LEFT JOIN (
SELECT b.*
FROM NUMBERS
LEFT OUTER JOIN (
SELECT a.*
FROM(
SELECT SELECT_PART.SLC_ID, ROW_NUMBER() OVER (ORDER BY SELECT_PART.SLC_ID) as
rowNumber, SELECT_PART.PCE_ID
FROM SELECT_PART
WHERE SELECT_PART.SLC_ID = (must be the same as sp.SLC_ID and can''t hardcode it)
) a
) b
ON b.rowNumber = NUMBERS.rowNumber
) c ON c.SLC_ID = sp.SLC_ID
ORDER BY sp.SLC_ID, c.rowNumber
NOTE: Max value for this solution is 2047
CREATE TABLE (
A INT NOT NULL,
B INT NOT NULL
)
A is an enumerated values of 1, 2, 3, 4, 5
B can be any values
I would like to count() the number of occurrence group by B, with a specific subset of A e.g. {1, 2}
Example:
A B
1 7 *
2 7 *
3 7
1 8 *
2 8 *
1 9
3 9
When B = 7, A = 1, 2, 3. Good
When B = 8, A = 1, 2. Good
When B = 9, A = 1, 3. Not satisfy, 2 is missing
So the count will be 2 (when B = 7 and 8)
If I've understood you correctly, we want to find B values for which we have both a 1 and a 2 in A, and then we want to know how many of those we have.
This query does this:
declare #t table (A int not null, B int not null)
insert into #t(A,B) values
(1,7),
(2,7),
(3,7),
(1,8),
(2,8),
(1,9),
(3,9)
select COUNT(DISTINCT B) from (
select B
from #t
where A in (1,2)
group by B
having COUNT(DISTINCT A) = 2
) t
One or both of the DISTINCTs may be unnecessary - it depends on whether your data can contain repeating values.
If I understand correctly and the requirement is to find Bs with a series of As that doesn't have any "gaps", you could compare the difference between the minimal and maximal A with number of records (per B, of course):
SELECT b
FROM mytable
GROUP BY b
HAVING COUNT(*) + 1 = MAX(a) - MIN(a)
SELECT COUNT(DISTINCT B) FROM TEMP T WHERE T.B NOT IN
(SELECT B FROM
(SELECT B,A,
LAG (A,1) OVER (PARTITION BY B ORDER BY A) AS PRE_A
FROM Temp) K
WHERE K.PRE_A IS NOT NULL AND K.A<>K.PRE_A+1);
table A
no date count
1 20160401 1
1 20160403 4
2 20160407 3
result
no date count
1 20160401 1
1 20160402 0
1 20160403 4
1 20160404 0
.
.
.
2 20160405 0
2 20160406 0
2 20160407 3
.
.
.
I'm using Oracle and I want to write a query that returns rows for every date within a range based on table A.
Is there some function in Oracle that can help me?
you can use the SEQUENCES.
First create a sequence
Create Sequence seq_name start with 20160401 max n;
where n is the max value till u want to display.
Then use the sql
select seq_name.next,case when seq_name.next = date then count else 0 end from tableA;
Note:- Its better not to use date,count as the column names.
Try this:
with
A as (
select 1 no, to_date('20160401', 'yyyymmdd') dat, 1 cnt from dual union all
select 1 no, to_date('20160403', 'yyyymmdd') dat, 4 cnt from dual union all
select 2 no, to_date('20160407', 'yyyymmdd') dat, 3 cnt from dual),
B as (select min(dat) mindat, max(dat) maxdat from A t),
C as (select level + mindat - 1 dat from B connect by level + mindat - 1 <= maxdat),
D as (select distinct no from A),
E as (select * from D,C)
select E.no, E.dat, nvl(cnt, 0) cnt
from E
full outer join A on A.no = E.no and A.dat = E.dat
order by 1, 2, 3
This isn't an oracle specific answer, you'll need to translate it to oracle yourself.
Create an intervals table, containing all integers from 0 to 999. Something like this:
CREATE TABLE intervals (days int);
INSERT INTO intervals (days) VALUES (0), (1);
DECLARE #rc int;
SELECT #rc = 2;
WHILE (SELECT Count(*) FROM intervals) < 1000 BEGIN
INSERT INTO intervals (days) SELECT days + #rc FROM intervals WHERE days + #rc < 1000;
SELECT #rc = #rc * 2
END;
Then all the dates in the range can be identified by adding intervals.days to the first date you've got, where the first date + intervals.days is <= the end date, and the resultant date is new. Do this by cross joining intervals to your own table. Something like (it would be in SQL, but again you'll need to translate):
SELECT DateAdd(a.date, d, i.days)
FROM (select min(date) from table_A) a, intervals I
WHERE DateAdd(a.date, d, i.days) < (select max(date) from table_A)
AND NOT EXISTS (select 1 from table_A aa where aa.date = DateAdd(a.date, d, i.days))
Hope this gives you a starting point
Given the following SQL Server table with a single char(1) column:
Value
------
'1'
'2'
'3'
How do I obtain the following results in T-SQL?
Result
------
'1+2+3'
'1+3+2'
'2+1+3'
'2+3+1'
'3+2+1'
'3+1+2'
This needs to be dynamic too, so if my table only holds rows '1' and '2' I'd expect:
Result
------
'1+2'
'2+1'
It seems like I should be able to use CROSS JOIN to do this, but since I don't know how many rows there will be ahead of time, I'm not sure how many times to CROSS JOIN back on myself..?
SELECT a.Value + '+' + b.Value
FROM MyTable a
CROSS JOIN MyTable b
WHERE a.Value <> b.Value
There will always be less than 10 (and really more like 1-3) rows at any given time. Can I do this on-the-fly in SQL Server?
Edit: ideally, I'd like this to happen in a single stored proc, but if I have to use another proc or some user defined functions to pull this off I'm fine with that.
This SQL will compute the permutations without repetitions:
WITH recurse(Result, Depth) AS
(
SELECT CAST(Value AS VarChar(100)), 1
FROM MyTable
UNION ALL
SELECT CAST(r.Result + '+' + a.Value AS VarChar(100)), r.Depth + 1
FROM MyTable a
INNER JOIN recurse r
ON CHARINDEX(a.Value, r.Result) = 0
)
SELECT Result
FROM recurse
WHERE Depth = (SELECT COUNT(*) FROM MyTable)
ORDER BY Result
If MyTable contains 9 rows, it will take some time to compute, but it will return 362,880 rows.
Update with explanation:
The WITH statement is used to define a recursive common table expression. In effect, the WITH statement is looping multiple times performing a UNION until the recursion is finished.
The first part of SQL sets the starting records. Assuming 3 rows named 'A', 'B', and 'C' in MyTable, this will generate these rows:
Result Depth
------ -----
A 1
B 1
C 1
Then the next block of SQL performs the first level of recursion:
SELECT CAST(r.Result + '+' + a.Value AS VarChar(100)), r.Depth + 1
FROM MyTable a
INNER JOIN recurse r
ON CHARINDEX(a.Value, r.Result) = 0
This takes all of the records generated so far (which will be in the recurse table) and joins them to all of the records in MyTable again. The ON clause filters the list of records in MyTable to only return the ones that do not exist already in this row's permutation. This would result in these rows:
Result Depth
------ -----
A 1
B 1
C 1
A+B 2
A+C 2
B+A 2
B+C 2
C+A 2
C+B 2
Then the recursion loops again giving these rows:
Result Depth
------ -----
A 1
B 1
C 1
A+B 2
A+C 2
B+A 2
B+C 2
C+A 2
C+B 2
A+B+C 3
A+C+B 3
B+A+C 3
B+C+A 3
C+A+B 3
C+B+A 3
At this point, the recursion stops because the UNION does not create any more rows because the CHARINDEX will always be 0.
The last SQL filters all of the resulting rows where the computed Depth column matches the # of records in MyTable. This throws out all of the rows except for the ones generated by the last depth of recursion. So the final result will be these rows:
Result
------
A+B+C
A+C+B
B+A+C
B+C+A
C+A+B
C+B+A
You can do this with a recursive CTE:
with t as (
select 'a' as value union all
select 'b' union all
select 'c'
),
const as (select count(*) as cnt from t),
cte as (
select cast(value as varchar(max)) as value, 1 as level
from t
union all
select cte.value + '+' + t.value, 1 + level
from cte join
t
on '+'+cte.value+'+' not like '%+'+t.value+'+%' cross join
const
where level <= const.cnt
)
select cte.value
from cte cross join
const
where level = const.cnt;
I would like to use the IN clause, but with the convert function.
Basically, I have a table (A) with the column of type int.
But in the other table (B) I Have values which are of type varchar.
Essentially, what I am looking for something like this
select *
from B
where myB_Column IN (select myA_Columng from A)
However, I am not sure if the int from table A, would map / convert / evaluate properly for the varchar in B.
I am using SQL Server 2008.
You can use CASE statement in where clause like this and CAST only if its Integer.
else 0 or NULL depending on your requirements.
SELECT *
FROM B
WHERE CASE ISNUMERIC(myB_Column) WHEN 1 THEN CAST(myB_Column AS INT) ELSE 0 END
IN (SELECT myA_Columng FROM A)
ISNUMERIC will be 1 (true) for Decimal values as-well so ideally you should implement your own IsInteger UDF .To do that look at this question
T-sql - determine if value is integer
Option #1
Select * from B where myB_Column IN
(
Select Cast(myA_Columng As Int) from A Where ISNUMERIC(myA_Columng) = 1
)
Option #2
Select B.* from B
Inner Join
(
Select Cast(myA_Columng As Int) As myA_Columng from A
Where ISNUMERIC(myA_Columng) = 1
) T
On T.myA_Columng = B.myB_Column
Option #3
Select B.* from B
Left Join
(
Select Cast(myA_Columng As Int) As myA_Columng from A
Where ISNUMERIC(myA_Columng) = 1
) T
On T.myA_Columng = B.myB_Column
I will opt third one. Reason is below mentioned.
Disadvantages of IN Predicate
Suppose I have two list objects.
List 1 List 2
1 12
2 7
3 8
4 98
5 9
6 10
7 6
Using Contains, it will search for each List-1 item in List-2 that means iteration will happen 49 times !!!
You can also use exists caluse,
select *
from B
where EXISTS (select 1 from A WHERE CAST(myA_Column AS VARCHAR) = myB_Column)
You can use below query :
select B.*
from B
inner join (Select distinct MyA_Columng from A) AS X ON B.MyB_Column = CAST(x.MyA_Columng as NVARCHAR(50))
Try it by using CAST()
SELECT *
FROM B
WHERE CAST(myB_Column AS INT(11)) IN (
SELECT myA_Columng
FROM A
)