Valori cumulativi delle colonne dalle date correnti e precedenti

Question

Ho una tabella di registrazioni, circa 300K record. Ho bisogno di una dichiarazione SQL che mostrerà il numero totale di registrazioni per quel particolare giorno?

select 
count('x'),CONVERT(varchar(12),date_created,111) 
from reg group by 
cONVERT(varchar(12),date_created,111) 
order by 
CONVERT(varchar(12),date_created,111) 

risultato di questa query:

169  2011/03/24 
3016  2011/03/25 
2999  2011/03/26 

Risultato desiderato:

2011/03/25 3016+169 
2011/03/26 2999+3016+169 

Come si può fare?

Answer 1

Ecco due versioni per fare questo. Ho provato con 100000 righe distribuite su 6000 giorni su un computer veramente lento con memoria insufficiente, e questo dimostra che la versione cte è più veloce della versione loop. Le altre versioni suggerite qui (finora) sono molto più lente, a condizione che abbia compreso correttamente il problema.

CTE ricorsiva (10 secondi)

-- Table variable to hold count for each day 
declare @DateCount table(d int, c int, rn int) 
insert into @DateCount 
    select 
    datediff(d, 0, date_created) as d, 
    count(*) as c, 
    row_number() over(order by datediff(d, 0, date_created)) as rn 
    from reg 
    group by datediff(d, 0, date_created) 

-- Recursive cte using @DateCount to calculate the running sum 
;with DateSum as 
(
    select 
    d, c, rn 
    from @DateCount 
    where rn = 1 
    union all 
    select 
    dc.d, ds.c+dc.c as c, dc.rn 
    from DateSum as ds 
    inner join @DateCount as dc 
     on ds.rn+1 = dc.rn 
) 
select 
    dateadd(d, d, 0) as date_created, 
    c as total_num 
from DateSum 
option (maxrecursion 0) 

Loop (14 secondi)

-- Table variable to hold count for each day 
declare @DateCount table(d int, c int, rn int, cr int) 
insert into @DateCount 
    select 
    datediff(d, 0, date_created) as d, 
    count(*) as c, 
    row_number() over(order by datediff(d, 0, date_created)) as rn, 
    0 
    from reg 
    group by datediff(d, 0, date_created) 

declare @rn int = 1 

-- Update cr with running sum 
update dc set 
    cr = dc.c 
from @DateCount as dc 
where rn = @rn 

while @@rowcount = 1 
begin 
    set @rn = @rn + 1 

    update dc set 
    cr = dc.c + (select cr from @DateCount where rn = @rn - 1) 
    from @DateCount as dc 
    where rn = @rn 
end 

-- Get the result 
select 
    dateadd(d, d, 0) as date_created, 
    cr as total_num 
from @DateCount 

Modifica 1 La versione veramente veloce

The quirky update

-- Table variable to hold count for each day 
declare @DateCount table(d int primary key, c int, cr int) 
insert into @DateCount 
    select 
    datediff(d, 0, date_created) as d, 
    count(*) as c, 
    0 
    from reg 
    group by datediff(d, 0, date_created) 

declare @rt int = 0 
declare @anchor int 

update @DateCount set 
    @rt = cr = @rt + c, 
    @anchor = d 
option (maxdop 1) 

-- Get the result 
select 
    dateadd(d, d, 0) as date_created, 
    cr as total_num 
from @DateCount     
order by d 

Answer 2

Prova questo.

SELECT r1.date_created, 
    COUNT(*) AS number 
FROM (SELECT distinct(date_created) FROM reg) AS r1 
    LEFT JOIN reg AS r2 ON (r2.date_created <= r1.date_created) 
GROUP BY r1.date_created 

Naturalmente si deve indicizzare il tuo tavolo con qualcosa di simile:

CREATE INDEX datefilter ON reg (date_created); 

Answer 3

Basta usare un SUM per ottenere un conteggio cumulativo:

SELECT reg1.date_created,  
     SUM(reg2.val) AS CumulativeValue 
FROM (
     select count(*) as RegCountForDay, 
       date_created 
     from reg 
     group by date_created 
    ) AS reg1 
LEFT JOIN reg AS reg2 ON (reg2.date_created <= reg1.date_created) 
GROUP BY reg1.date_created 

Answer 4

Attualmente si hanno 2 opzioni: prima sta usando join come proposto da vbence, il secondo è sottoquery:

SELECT r1.date_created, (SELECT COUNT(*) FROM reg r2 
WHERE r2.date_created<=r1.date_created) AS total_num 
FROM reg r1; 

Questi due approcci generano piani di esecuzione simili.

In futuro, quando SQLServer implementa ORDER BY per OVER con funzioni di aggregazione, si sarà in grado di scrivere

SELECT date_created, 
COUNT(*) OVER(ORDER BY date_created) as total_num 
FROM reg; 

Answer 5

Un'altra opzione è quella di utilizzare CLR per definire la propria funzione di Esecuzione Sum come descritto nel link followig:

http://pavelpawlowski.wordpress.com/2010/09/30/sql-server-and-fastest-running-totals-using-clr/

Answer 6

si può risolvere questo problema attraverso query SQL di seguito ..Hai dato due colonne col1=Number e col2=Date

Select DATE,OUTPUT=SUM(InnerValue) from 
(
    Select T1.Date, T1.Number, InnerValue=ISNULL(T2.Number,0) from 
    (
    Select ID=DENSE_RANK() OVER(ORDER BY DATE),Date,Number from YourTable 
) As T1 
    LEFT JOIN 
    (
    Select ID=DENSE_RANK() OVER(ORDER BY DATE),Date,Number from YourTable 
) AS T2 
    ON T1.ID >= T2.ID 
) As MainTable GROUP BY DATE