Funzione SQL Row_Number() in Where Clausola

Question

Ho trovato una risposta alla domanda con la funzione Row_Number() nella clausola where. Quando ho provato una query, mi è stato sempre il seguente errore:

"Msg 4108, Level 15, State 1, Line 1 Windowed functions can only appear in the SELECT or ORDER BY clauses."

Ecco l'interrogazione ho provato. Se qualcuno sa come risolvere questo, per favore fatemelo sapere.

SELECT employee_id 
FROM V_EMPLOYEE 
WHERE row_number() OVER (ORDER BY employee_id) > 0 
ORDER BY Employee_ID 

Answer 1

SELECT employee_id 
FROM (
     SELECT employee_id, ROW_NUMBER() OVER (ORDER BY employee_id) AS rn 
     FROM V_EMPLOYEE 
     ) q 
WHERE rn > 0 
ORDER BY 
     Employee_ID 

noti che questo filtro è ridondante: ROW_NUMBER() parte da 1 ed è sempre maggiore di 0.

Answer 2

Per aggirare questo problema, racchiudere l'istruzione select in un CTE e quindi eseguire una query sul CTE e utilizzare i risultati della funzione windowed nella clausola where.

WITH MyCte AS 
(
    select employee_id, 
      RowNum = row_number() OVER (order by employee_id) 
    from  V_EMPLOYEE 
    ORDER BY Employee_ID 
) 
SELECT employee_id 
FROM MyCte 
WHERE RowNum > 0 

Answer 3

Penso che si desidera qualcosa di simile:

SELECT employee_id 
FROM (SELECT employee_id, row_number() 
     OVER (order by employee_id) AS 'rownumber' 
     FROM V_EMPLOYEE) TableExpressionsMustHaveAnAliasForDumbReasons 
WHERE rownumber > 0 

Answer 4

Utilizzando CTE (SQL Server 2005 +):

WITH employee_rows AS (
    SELECT t.employee_id, 
     ROW_NUMBER() OVER (ORDER BY t.employee_id) 'rownum' 
    FROM V_EMPLOYEE t) 
SELECT er.employee_id 
    FROM employee_rows er 
WHERE er.rownum > 1 

Utilizzando vista in linea/non-CTE alternativo equivalente:

SELECT er.employee_id 
    FROM (SELECT t.employee_id, 
       ROW_NUMBER() OVER (ORDER BY t.employee_id) 'rownum' 
      FROM V_EMPLOYEE t) er 
WHERE er.rownum > 1 

Answer 5

In risposta ai commenti su rexem's risposta, per quanto riguarda se una vista in linea o CTE sarebbe più veloce, ho rifuso le query per usare una tabella I, e tutti, avevano a disposizione: sys.objects.

WITH object_rows AS (
    SELECT object_id, 
     ROW_NUMBER() OVER (ORDER BY object_id) RN 
    FROM sys.objects) 
SELECT object_id 
FROM object_rows 
WHERE RN > 1 

SELECT object_id 
FROM (SELECT object_id, 
     ROW_NUMBER() OVER (ORDER BY object_id) RN 
    FROM sys.objects) T 
WHERE RN > 1 

I piani di query prodotti erano esattamente gli stessi. Mi aspetto che in tutti i casi, Query Optimizer crei lo stesso piano, almeno nella semplice sostituzione di CTE con vista in linea o viceversa.

Naturalmente, prova le tue query sul tuo sistema per vedere se c'è una differenza.

Inoltre, row_number() nella clausola where è un errore comune nelle risposte fornite su Stack Overflow. Logicaly row_number() non è disponibile finché non viene elaborata la clausola select. Le persone dimenticano questo e quando rispondono senza testare la risposta, la risposta a volte è sbagliata. (Una carica Io stesso ho reso colpevole di.)

Answer 6

in base alla risposta del PO alla domanda:

Please see this link. Its having a different solution, which looks working for the person who asked the question. I'm trying to figure out a solution like this.

Paginated query using sorting on different columns using ROW_NUMBER() OVER() in SQL Server 2005

~Joseph

"Metodo 1" è come interrogazione del PO dalla questione legata, e "il metodo 2" è come la query dalla risposta selezionata. Dovevi controllare il codice collegato in questo answer per vedere cosa stava realmente accadendo, poiché il codice nella risposta selezionata è stato modificato per farlo funzionare.Prova questo:

DECLARE @YourTable table (RowID int not null primary key identity, Value1 int, Value2 int, value3 int) 
SET NOCOUNT ON 
INSERT INTO @YourTable VALUES (1,1,1) 
INSERT INTO @YourTable VALUES (1,1,2) 
INSERT INTO @YourTable VALUES (1,1,3) 
INSERT INTO @YourTable VALUES (1,2,1) 
INSERT INTO @YourTable VALUES (1,2,2) 
INSERT INTO @YourTable VALUES (1,2,3) 
INSERT INTO @YourTable VALUES (1,3,1) 
INSERT INTO @YourTable VALUES (1,3,2) 
INSERT INTO @YourTable VALUES (1,3,3) 
INSERT INTO @YourTable VALUES (2,1,1) 
INSERT INTO @YourTable VALUES (2,1,2) 
INSERT INTO @YourTable VALUES (2,1,3) 
INSERT INTO @YourTable VALUES (2,2,1) 
INSERT INTO @YourTable VALUES (2,2,2) 
INSERT INTO @YourTable VALUES (2,2,3) 
INSERT INTO @YourTable VALUES (2,3,1) 
INSERT INTO @YourTable VALUES (2,3,2) 
INSERT INTO @YourTable VALUES (2,3,3) 
INSERT INTO @YourTable VALUES (3,1,1) 
INSERT INTO @YourTable VALUES (3,1,2) 
INSERT INTO @YourTable VALUES (3,1,3) 
INSERT INTO @YourTable VALUES (3,2,1) 
INSERT INTO @YourTable VALUES (3,2,2) 
INSERT INTO @YourTable VALUES (3,2,3) 
INSERT INTO @YourTable VALUES (3,3,1) 
INSERT INTO @YourTable VALUES (3,3,2) 
INSERT INTO @YourTable VALUES (3,3,3) 
SET NOCOUNT OFF 

DECLARE @PageNumber  int 
DECLARE @PageSize  int 
DECLARE @SortBy   int 

SET @PageNumber=3 
SET @PageSize=5 
SET @SortBy=1 


--SELECT * FROM @YourTable 

--Method 1 
;WITH PaginatedYourTable AS (
SELECT 
    RowID,Value1,Value2,Value3 
     ,CASE @SortBy 
      WHEN 1 THEN ROW_NUMBER() OVER (ORDER BY Value1 ASC) 
      WHEN 2 THEN ROW_NUMBER() OVER (ORDER BY Value2 ASC) 
      WHEN 3 THEN ROW_NUMBER() OVER (ORDER BY Value3 ASC) 
      WHEN -1 THEN ROW_NUMBER() OVER (ORDER BY Value1 DESC) 
      WHEN -2 THEN ROW_NUMBER() OVER (ORDER BY Value2 DESC) 
      WHEN -3 THEN ROW_NUMBER() OVER (ORDER BY Value3 DESC) 
     END AS RowNumber 
    FROM @YourTable 
    --WHERE 
) 
SELECT 
    RowID,Value1,Value2,Value3,RowNumber 
     ,@PageNumber AS PageNumber, @PageSize AS PageSize, @SortBy AS SortBy 
    FROM PaginatedYourTable 
    WHERE RowNumber>=(@PageNumber-1)*@PageSize AND RowNumber<=(@PageNumber*@PageSize)-1 
    ORDER BY RowNumber 



-------------------------------------------- 
--Method 2 
;WITH PaginatedYourTable AS (
SELECT 
    RowID,Value1,Value2,Value3 
     ,ROW_NUMBER() OVER 
     (
      ORDER BY 
       CASE @SortBy 
        WHEN 1 THEN Value1 
        WHEN 2 THEN Value2 
        WHEN 3 THEN Value3 
       END ASC 
       ,CASE @SortBy 
        WHEN -1 THEN Value1 
        WHEN -2 THEN Value2 
        WHEN -3 THEN Value3 
       END DESC 
     ) RowNumber 
    FROM @YourTable 
    --WHERE more conditions here 
) 
SELECT 
    RowID,Value1,Value2,Value3,RowNumber 
     ,@PageNumber AS PageNumber, @PageSize AS PageSize, @SortBy AS SortBy 
    FROM PaginatedYourTable 
    WHERE 
     RowNumber>=(@PageNumber-1)*@PageSize AND RowNumber<=(@PageNumber*@PageSize)-1 
     --AND more conditions here 
    ORDER BY 
     CASE @SortBy 
      WHEN 1 THEN Value1 
      WHEN 2 THEN Value2 
      WHEN 3 THEN Value3 
     END ASC 
     ,CASE @SortBy 
      WHEN -1 THEN Value1 
      WHEN -2 THEN Value2 
      WHEN -3 THEN Value3 
     END DESC 

USCITA:

RowID Value1 Value2 Value3 RowNumber PageNumber PageSize SortBy 
------ ------ ------ ------ ---------- ----------- ----------- ----------- 
10  2  1  1  10   3   5   1 
11  2  1  2  11   3   5   1 
12  2  1  3  12   3   5   1 
13  2  2  1  13   3   5   1 
14  2  2  2  14   3   5   1 

(5 row(s) affected 

RowID Value1 Value2 Value3 RowNumber PageNumber PageSize SortBy 
------ ------ ------ ------ ---------- ----------- ----------- ----------- 
10  2  1  1  10   3   5   1 
11  2  1  2  11   3   5   1 
12  2  1  3  12   3   5   1 
13  2  2  1  13   3   5   1 
14  2  2  2  14   3   5   1 

(5 row(s) affected) 

Answer 7

Select * from 
(
    Select ROW_NUMBER() OVER (order by Id) as 'Row_Number', * 
    from tbl_Contact_Us 
) as tbl 
Where tbl.Row_Number = 5 

Answer 8

WITH MyCte AS 
(
    select 
     employee_id, 
     RowNum = row_number() OVER (order by employee_id) 
    from V_EMPLOYEE 
) 
SELECT employee_id 
FROM MyCte 
WHERE RowNum > 0 
ORDER BY employee_id 

Answer 9

se è necessario aggiungere condizioni dinamicamente, è possibile utilizzare esiste in tua ricerca:

SELECT f0.* 
FROM FOO f0 
WHERE EXISTS 
    (SELECT f2.foo_id 
    FROM 
    (SELECT foo_id , 
     ROW_NUMBER() OVER(PARTITION BY F1.BAR_ID ORDER BY F1.AMOUNT) rk 
    FROM foo f1 
    )f2 
    WHERE f0.foo_id=f2.foo_id 
    AND rk   =2 -- your condition on row_number goes here 
);