Group by sur un alias

[clusty]

Bonjour,

J'essaie de faire un group by sur un alias. D'après ce que j'ai compris, il faut faire une sous-requête. Pourtant, cela ne fonctionne pas:

Code :

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SELECT count(datetime), myYear
FROM (
  SELECT
     datetime, 
     (SELECT EXTRACT(year FROM datetime) FROM session) AS "myYear"
  FROM
     session
  ) AS inline
GROUP BY myYear;

J'ai l'erreur:

"SQL command not properly ended"

Qqn à une idée?
Merci.

[mnitu]

Ca marche mais pas de As pour la table et des guillemets par tout

Code :

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WITH v_session AS (
  SELECT sysdate AS datetime FROM dual
)
SELECT count(datetime), "myYear"
FROM (
  SELECT
     datetime, 
     (SELECT EXTRACT(year FROM datetime) FROM v_session) AS "myYear"
  FROM
     v_session
  ) inline
GROUP BY "myYear";

[clusty]

Merci pour l'aide. J'ai maintenant le code suivant:

Code :

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SELECT count(datetime), "myYear"
FROM (
  SELECT
     datetime, 
     (SELECT EXTRACT(year FROM datetime) FROM session) AS "myYear"
  FROM
     session
  ) inline
GROUP BY "myYear";

Avec cette fois l'erreur:

"ORA-01427: single-row subquery returns more than one row"

J'ai lu dans la doc, qui fallait utilisé ALL/ANY/etc. dans la requête extérieur, mais cela ne fonctionne pas non plus.

Une idée?
Merci.

[mnitu]

Les requêtes scalaires

Code :

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...
SELECT
     datetime, 
     (SELECT EXTRACT(year FROM datetime) FROM session) AS "myYear"...

ne peuvent ramener qu'au maximum une seule valeur

Code :

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Connected TO Oracle DATABASE 10g Enterprise Edition Release 10.2.0.4.0 
Connected AS mni
 
SQL> 
SQL> WITH v_session AS (
  2    SELECT sysdate AS datetime FROM dual union ALL
  3    SELECT sysdate - 1 AS datetime FROM dual
  4  )
  5  SELECT count(datetime), "myYear"
  6  FROM (
  7    SELECT
  8       datetime,
  9       EXTRACT(year FROM datetime) AS "myYear"
 10    FROM
 11       v_session
 12    ) inline
 13  GROUP BY "myYear"
 14  /
 
COUNT(DATETIME)     myYear
--------------- ----------
              2       2011
 
SQL>

[tedo01]

Bonjour,
On peut aussi faire le GROUP BY directement sur l'expression :

Code :

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WITH v_session(datetime) AS (
      SELECT sysdate      FROM dual union
      SELECT sysdate - 1 FROM dual
     )
SELECT   count(datetime), EXTRACT(year FROM datetime) AS "myYear"
FROM     v_session
GROUP BY EXTRACT(year FROM datetime)